View Filing Data

Costs of revenue, excluding depreciation and amortization

$ 1,617,804

$ 1,890,180

$ 3,014,638

$ 3,048,364

1,366,584

1,626,335

2,603,883

2,597,469

51,676

45,379

101,615

88,282

67,602

70,823

131,224

135,604

Interest expense, net

20,795

14,791

37,854

27,388

(5,824)

(6,060)

(11,409)

(7,706)

788

146

(2,301)

576

Provision for income taxes

116,183

138,766

153,772

206,751

(35,782)

(55,434)

(46,908)

(82,792)

Net (loss) income attributable to non-controlling interests

80,401

83,332

106,864

123,959

(91)

1,664

(188)

1,321

Basic earnings per share (in dollars per share)

^[1]

$ 80,492

$ 81,668

$ 107,052

$ 122,638

Earnings per share (Note 2):

$ 1.02

$ 1.01

$ 1.34

$ 1.52

Basic weighted average common shares outstanding

78,984

80,925

80,061

80,812

Diluted earnings per share (in dollars per share)

$ 1.01

$ 0.99

$ 1.32

$ 1.49

Diluted weighted average common shares outstanding

80,062

82,292

81,136

82,226

[1]	Calculated as total net income less amounts attributable to non-controlling interests.

Condensed Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 80,401	$ 83,332	$ 106,864	$ 123,959
Other comprehensive income (loss):
Foreign currency translation (losses) gains, net of tax	(1,652)	595	(2,175)	1,774
Unrealized gains (losses) on equity investee activity, net of tax	2,937	(2,730)	10,653	(2,095)
Comprehensive income	81,686	81,197	115,342	123,638
Comprehensive (loss) income attributable to non-controlling interests	(91)	1,664	(188)	1,321
Comprehensive income attributable to MasTec, Inc.	$ 81,777	$ 79,533	$ 115,530	$ 122,317

Goodwill and Intangible Assets Disclosure [Abstract]

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
-Paragraph 1A
-Subparagraph (a)
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (a)(1)
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
-Paragraph 1B
-Subparagraph (a)
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-Topic 280
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 6: http://www.xbrl.org/2003/role/exampleRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4K
-URI http://asc.fasb.org/extlink&oid=84234705&loc=SL4591552-111686

+ Details

Condensed Unaudited Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 20,684	$ 40,326
Accounts receivable, net (Note 5)	2,077,487	1,598,015
Inventories, net	100,231	76,992
Prepaid expenses	43,216	101,270
Other current assets	40,152	35,763
Total current assets	2,281,770	1,852,366
Property and equipment, net	739,425	706,506
Goodwill, net	1,146,599	1,137,738
Other intangible assets, net	181,515	191,142
Other long-term assets	232,848	178,824
Total assets	4,582,157	4,066,576
Current liabilities:
Current portion of long-term debt	84,215	87,866
Accounts payable	544,398	377,954
Accrued salaries and wages	108,647	89,087
Other accrued expenses	187,394	148,971
Billings in excess of costs and earnings	243,224	194,494
Other current liabilities	84,899	65,455
Total current liabilities	1,252,777	963,827
Long-term debt	1,532,978	1,280,706
Deferred income taxes	206,411	204,518
Other long-term liabilities	159,593	184,172
Total liabilities	3,151,759	2,633,223
Commitments and contingencies (Note 14)
Equity
Preferred stock, $1.00 par value: authorized shares - 5,000,000; issued and outstanding shares – none	0	0
Common stock, $0.10 par value: authorized shares - 145,000,000; issued shares - 91,080,280 and 90,935,584 (including 1,480,582 and 1,421,041 of unvested stock awards) as of June 30, 2018 and December 31, 2017, respectively	9,108	9,094
Capital surplus	783,825	775,387
Retained earnings	965,768	857,154
Accumulated other comprehensive loss	(55,234)	(63,712)
Treasury stock, at cost: 10,835,749 and 8,132,811 shares as of June 30, 2018 and December 31, 2017, respectively	(275,435)	(147,124)
Total MasTec, Inc. shareholders’ equity	1,428,032	1,430,799
Non-controlling interests	2,366	2,554
Total equity	1,430,398	1,433,353
Total liabilities and equity	$ 4,582,157	$ 4,066,576

Condensed Unaudited Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized	145,000,000	145,000,000
Common stock, shares issued	91,080,280	90,935,584
Treasury stock, shares	10,835,749	8,132,811
Restricted Stock Awards [Member] \| Common Stock [Member]
Unvested stock awards (in shares)	1,480,582	1,421,041

Condensed Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 106,864	$ 123,959
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	101,615	88,282
Non-cash interest expense, net	1,451	1,615
Non-cash stock-based compensation expense	6,571	7,166
(Benefit from) provision for deferred income taxes	(172)	76,584
Equity in earnings of unconsolidated affiliates	(11,409)	(7,706)
Gains on sales of assets, net, including fixed assets held-for-sale	(6,920)	(1,873)
Other non-cash items, net	2,686	13,190
Changes in assets and liabilities, net of acquisitions:
Accounts receivable, net	(471,716)	(388,818)
Inventories	(8,550)	28,295
Other assets, current and long-term portion	58,949	(81,286)
Accounts payable and accrued expenses	180,150	113,975
Billings in excess of costs and earnings	44,524	(58,594)
Book overdrafts	8,361	(9,760)
Other liabilities, current and long-term portion	10,813	(5,189)
Net cash provided by (used in) operating activities	23,217	(100,160)
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired	(6,684)	(37,444)
Capital expenditures	(87,997)	(56,853)
Proceeds from sale of property and equipment	13,884	7,369
Payments for other investments	(35,713)	(74,482)
Proceeds from other investments	5,415	12,118
Net cash used in investing activities	(111,095)	(149,292)
Cash flows from financing activities:
Proceeds from credit facilities	1,638,874	1,153,230
Repayments of credit facilities	(1,374,552)	(869,100)
Repayments of other borrowings	(15,800)	(10,291)
Payments of capital lease obligations	(37,926)	(30,858)
Payments of acquisition-related contingent consideration	(15,929)	(6,676)
Repurchase of common stock	(128,311)	0
Distributions to non-controlling interests	(559)	(1,280)
Proceeds from stock-based awards, net	1,927	5
Other financing activities	0	(6,240)
Net cash provided by financing activities	67,724	228,790
Effect of currency translation on cash	512	125
Net decrease in cash and cash equivalents	(19,642)	(20,537)
Cash and cash equivalents - beginning of period	40,326	38,767
Cash and cash equivalents - end of period	20,684	18,230
Supplemental cash flow information:
Interest paid	36,068	25,743
Income tax (refunds) payments, net	(13,975)	76,633
Supplemental disclosure of non-cash information:
Additions to acquisition-related contingent consideration	3,510	25,000
Equipment acquired under capital lease and financing arrangements	39,548	109,914
Accrued capital expenditures	$ 12,315	$ 1,499

Business, Basis of Presentation and Significant Accounting Policies	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Business, Basis of Presentation and Significant Accounting Policies	Note 1 – Business, Basis of Presentation and Significant Accounting Policies Nature of the Business MasTec, Inc. (collectively with its subsidiaries, “MasTec” or the “Company”) is a leading infrastructure construction company operating mainly throughout North America across a range of industries. The Company’s primary activities include the engineering, building, installation, maintenance and upgrade of communications, energy and utility infrastructure, such as: wireless, wireline/fiber, install-to-the-home and customer fulfillment activities; petroleum and natural gas pipeline infrastructure; electrical utility transmission and distribution; power generation; heavy civil; and industrial infrastructure. MasTec’s customers are primarily in these industries. MasTec reports its results under five reportable segments: (1) Communications; (2) Oil and Gas; (3) Electrical Transmission; (4) Power Generation and Industrial; and (5) Other. Basis of Presentation The accompanying condensed unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions for Form 10-Q and Rule 10-01 of Regulation S-X. Pursuant to these rules and regulations, certain information and footnote disclosures normally included in the annual audited consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The accompanying condensed consolidated balance sheet as of December 31, 2017 is derived from the Company’s audited financial statements as of that date. Because certain information and footnote disclosures have been condensed or omitted, these condensed unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto as of and for the year ended December 31, 2017 contained in the Company’s 2017 Annual Report on Form 10-K (the “2017 Form 10-K”). In management’s opinion, all normal and recurring adjustments considered necessary for a fair presentation of the financial position, results of operations and cash flows for the periods presented have been included. Certain prior year amounts have been reclassified to conform to the current period presentation. Interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. The Company believes that the disclosures made in these condensed unaudited consolidated financial statements are adequate to make the information not misleading. Principles of Consolidation The accompanying condensed unaudited consolidated financial statements include MasTec, Inc. and its subsidiaries and include the accounts of all majority owned subsidiaries over which the Company exercises control and, when applicable, entities in which the Company has a controlling financial interest. All significant intercompany balances and transactions have been eliminated in consolidation. Other parties’ interests in entities that MasTec consolidates are reported as non-controlling interests within equity. Net income or loss attributable to non-controlling interests is reported as a separate line item below net income or loss. The Company’s investments in entities for which the Company does not have a controlling interest, but for which it has the ability to exert significant influence, are accounted for using the equity method of accounting. Equity method investments are recorded as other long-term assets. Income or loss from these investments is recorded as a separate line item in the statements of operations. Intercompany profits or losses associated with the Company’s equity method investments are eliminated until realized by the investee in transactions with third parties. For equity investees in which the Company has an undivided interest in the assets, liabilities and profits or losses of an unincorporated entity, but the Company does not exercise control over the entity, the Company consolidates its proportional interest in the accounts of the entity. Equity investments, other than those accounted for as equity method investments or those that are consolidated, are measured at fair value if their fair values are readily determinable. Equity investments that do not have readily determinable fair values are measured at cost, adjusted for changes from observable market transactions, less impairment. Realized and unrealized gains or losses related to equity investments are recognized in other income or expense. Management determines whether each business entity in which it has equity interests, debt, or other investments constitutes a variable interest entity (“VIE”) based on the nature and characteristics of such arrangements. If an investment arrangement is determined to be a VIE, then management determines if the Company is the VIE’s primary beneficiary by evaluating several factors, including the Company’s: (i) risks and responsibilities; (ii) ownership interests; (iii) decision making powers; and (iv) financial interests, among other factors. If management determines the Company is the primary beneficiary of a VIE, then it would be consolidated, and other parties’ interests in the VIE would be accounted for as non-controlling interests. The primary beneficiary consolidating the VIE must normally have both (i) the power to direct the primary activities of the VIE and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE, which, in either case, could be significant to the VIE. As of June 30, 2018, the Company determined that certain of its investment arrangements were VIEs. The Company does not, however, have the power to direct the primary activities that most significantly impact the economic performance of these VIEs and the Company is not the primary beneficiary; accordingly, it has not consolidated these VIEs. Translation of Foreign Currencies The assets and liabilities of foreign subsidiaries with a functional currency other than the U.S. dollar are translated into U.S. dollars at period-end exchange rates, with resulting translation gains or losses accumulated within other comprehensive income or loss. Revenue and expenses are translated into U.S. dollars at average rates of exchange during the applicable period. Substantially all of the Company’s foreign operations use their local currency as their functional currency. Currency gains or losses resulting from transactions executed in currencies other than the functional currency are included in other income or expense, net. In these condensed unaudited consolidated financial statements, “$” means U.S. dollars unless otherwise noted. Management Estimates The preparation of consolidated financial statements in accordance with U.S. GAAP requires the use of estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. These estimates are based on historical experience and various other assumptions, the results of which form the basis of making judgments about the Company’s operating results and the carrying values of assets and liabilities that are not readily apparent from other sources. Key estimates include: the recognition of revenue and project profit or loss, which the Company defines as project revenue, less project costs of revenue, including project-related depreciation, in particular, on construction contracts accounted for under the cost-to-cost method, for which the recorded amounts require estimates of costs to complete and the amount of variable consideration included in the contract transaction price; allowances for doubtful accounts; fair value estimates, including those related to business acquisitions, valuations of goodwill and intangible assets, acquisition-related contingent consideration and equity investments; asset lives used in computing depreciation and amortization; fair values of financial instruments; self-insurance liabilities; other accruals and allowances; income taxes; and the estimated effects of litigation and other contingencies. While management believes that such estimates are reasonable when considered in conjunction with the Company’s consolidated financial position and results of operations taken as a whole, actual results could differ materially from those estimates. Significant Accounting Policies Revenue Recognition The Company adopted the requirements of Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which is also referred to as Accounting Standards Codification (“ASC”) Topic 606 (“Topic 606”), under the modified retrospective transition approach effective January 1, 2018, with application to all existing contracts that were not substantially completed as of January 1, 2018. The difference between the recognition criteria under Topic 606 and the Company’s previous revenue recognition practices under the previous revenue recognition guidance, ASC Topic 605-35, was recognized through a cumulative effect adjustment of approximately $2 million that was made to the opening balance of retained earnings as of January 1, 2018. Consistent with the modified retrospective transition approach, the comparative 2017 prior period was not adjusted to conform to the current period presentation. Under Topic 606, revenue is recognized when, or as, control of promised goods and services is transferred to customers, and the amount of revenue recognized reflects the consideration to which an entity expects to be entitled in exchange for the goods and services transferred. The adoption of Topic 606 did not have, and is not expected to have, a material effect on the timing or amount of revenue recognized as compared with the Company’s previous revenue recognition practices. Revenue is recognized by the Company primarily over time utilizing the cost-to-cost measure of progress for fixed price contracts and certain master service and other service agreements, consistent with the Company’s previous revenue recognition practices. Under Topic 606, the cost-to-cost measure of progress best depicts the transfer of control of goods or services to the customer for these contracts. Contracts. The Company derives revenue primarily from construction projects performed: i) under master and other service agreements, which provide a menu of available services in a specific geographic territory that are utilized on an as-needed basis, and are typically priced using time and materials or a fixed price per unit basis; or ii) under contracts for specific projects requiring the construction and installation of an entire infrastructure system or specified units within an infrastructure system, which are subject to multiple pricing options, including fixed price, unit price, time and materials, or cost plus a markup. Revenue derived from master service and other service agreements totaled 37% and 31% of consolidated revenue for the three month periods ended June 30, 2018 and 2017, respectively, and totaled 38% and 37% for the six month periods ended June 30, 2018 and 2017, respectively. Fixed price contracts provide for a fixed amount of revenue for the entire project. Revenue from these contracts, as well as for certain projects pursuant to master and other service agreements, is recognized over time using the cost-to-cost measure of progress. For these contracts, the cost-to-cost measure of progress best depicts the continuous transfer of control of goods or services to the customer. Such contracts provide that the customer accept completion of progress to date and compensate the Company for services rendered. For certain of the Company’s master service and other service agreements, under which it performs installation and maintenance services, primarily for install-to-the-home service providers in its Communications segment, revenue is recognized at a point in time. This is generally when the work order has been fulfilled, which is typically the same day the work is initiated. Point in time revenue accounted for approximately 7% and 8% of consolidated revenue for the three and six month periods ended June 30, 2018, respectively. Substantially all of the Company’s other revenue is recognized over time. Contract costs include all direct materials, labor and subcontracted costs, as well as indirect costs related to contract performance, such as indirect labor, supplies, tools, repairs and the operational costs of capital equipment. The cost estimation process for recognizing revenue over time under the cost-to-cost method is based on the professional knowledge and experience of the Company’s project managers, engineers and financial professionals. Management reviews estimates of total contract transaction price and total project costs on an ongoing basis. Changes in job performance, job conditions and management’s assessment of expected variable consideration are factors that influence estimates of the total contract transaction price, total costs to complete those contracts and profit recognition. Changes in these factors could result in revisions to revenue in the period in which the revisions are determined, which could materially affect the Company’s consolidated results of operations for that period. Provisions for losses on uncompleted contracts are recorded in the period in which such losses are determined. For both the six month periods ended June 30, 2018 and 2017, project profit was affected by less than 5% as a result of changes in contract estimates included in projects that were in process as of December 31, 2017 and 2016. Revenue recognized for the three and six month periods ended June 30, 2018 from performance obligations satisfied, or work completed, in prior periods totaled approximately $5.2 million and $47.4 million, respectively, which represents the effect on revenue for the periods presented of changes in transaction prices from variable consideration on certain projects. The timing of customer billings is generally dependent upon advance billing terms, milestone billings based on the completion of certain phases of the work, or when services are provided. Under the typical payment terms of master and other service agreements and fixed price contracts, the customer makes progress payments based on quantifiable measures of performance by the Company as defined by each specific agreement. Progress payments, generally net of amounts retained, are paid by the customer over the duration of the contract. For install-to-the-home contracts, work orders are billed and paid as completed. Amounts billed and due from customers, as well as the amount of contract assets, are classified within accounts receivable, net, in the consolidated balance sheets. See Note 5 - Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities for related discussion. Amounts expected to be collected beyond one year are classified as other long-term assets. Performance Obligations. A performance obligation is a contractual promise to transfer a distinct good or service to a customer, and is the unit of account under Topic 606. The transaction price of a contract is allocated to each distinct performance obligation and recognized as revenue when or as the performance obligation is satisfied. The Company’s contracts often require significant integration services, and even when delivering multiple distinct services, are generally accounted for as a single performance obligation. Contract amendments and change orders are generally not distinct from the existing contract and are accounted for as a modification of the existing contract and performance obligation. The majority of the Company’s performance obligations are completed within one year. When more than one contract is entered into with a customer on or close to the same date, the Company evaluates whether those contracts should be combined and accounted for as a single contract as well as whether those contracts should be accounted for as one, or more than one, performance obligation. This evaluation requires significant judgment and is based on the facts and circumstances of the various contracts. Remaining performance obligations represent the amount of unearned transaction prices under contracts for which work is wholly or partially unperformed. As of June 30, 2018, the amount of the Company’s remaining performance obligations was $5.1 billion. The Company expects to recognize approximately $3.0 billion of its remaining performance obligations as revenue during the remainder of 2018, with the balance to be recognized primarily in 2019. Variable Consideration. Transaction prices for the Company’s contracts may include variable consideration, which comprises items such as change orders, claims, incentives and liquidated damages. Management estimates variable consideration for a performance obligation utilizing estimation methods that best predict the amount of consideration to which the Company will be entitled. Variable consideration is included in the estimated transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Management’s estimates of variable consideration and determination of whether to include estimated amounts in transaction price are based largely on engineering studies and legal opinions, past practices with the customer, specific discussions, correspondence or preliminary negotiations with the customer and all other relevant information that is reasonably available. The effect of variable consideration on the transaction price of a performance obligation is typically recognized as an adjustment to revenue on a cumulative catch-up basis. To the extent unapproved change orders, claims and liquidated damages reflected in transaction price are not resolved in the Company’s favor, or to the extent incentives reflected in transaction price are not earned, there could be reductions in, or reversals of, previously recognized revenue. As of June 30, 2018 and December 31, 2017, the Company included approximately $190 million and $146 million, respectively, of change orders and/or claims in the transaction price for certain contracts that were in the process of being resolved in the normal course of business, including through negotiation, arbitration and other proceedings. These transaction price adjustments are included within costs and earnings in excess of billings or accounts receivable, net of allowance, as appropriate. As of both June 30, 2018 and December 31, 2017, these change orders and/or claims were primarily related to certain large long-haul pipeline construction projects in the Oil and Gas segment that have either recently been completed, or are expected to reach substantial completion in the coming months. The Company actively engages with its customers to complete the final approval process, and generally expects these processes to be completed within one year. Amounts ultimately realized upon final acceptance by customers could be higher or lower than such estimated amounts. Recently Issued Accounting Pronouncements See the revenue recognition discussion within Significant Accounting Policies above, and the recent accounting pronouncements discussion below, for information pertaining to the effects of recently adopted and other recent accounting pronouncements, as updated from the discussion in the Company’s 2017 Form 10-K. Other Accounting Pronouncements Adopted in 2018 In August 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”) to reduce diversity in practice by providing guidance on the classification of certain cash receipts and payments in the statement of cash flows. This ASU, which the Company adopted as of January 1, 2018, is effective on a retrospective basis, and resulted in the reclassification of certain types of activity in the consolidated statement of cash flows, including the reclassification of $12 million of second quarter 2017 acquisition-related contingent consideration payments in excess of acquisition date liabilities from financing to operating cash flows. Additionally, in connection with the adoption of this ASU, the Company elected to account for distributions received from equity method investees using the nature of distributions approach, under which distributions are classified based on the nature of the activity that generated them. The other provisions of this ASU did not have a material effect on the Company’s consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which was further amended in February and in March 2018 by ASU 2018-03, Technical Corrections and Improvements to Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2018-03”) and ASU 2018-04, Investments - Debt Securities (Topic 320) and Regulated Operations (Topic 980):Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 117 and SEC Release No. 33-9273 (“ASU 2018-04”) to clarify certain aspects of ASU 2016-01 and to update Securities and Exchange Commission (“SEC”) interpretive guidance in connection with the provisions of ASU 2016-01. These ASUs provide guidance for the recognition, measurement, presentation and disclosure of financial assets and financial liabilities, including equity investments other than those accounted for under the equity method of accounting or those that are consolidated. Equity investments within the scope of these ASUs are required to be measured at fair value with changes in fair value recognized in net income. Equity investments that do not have readily determinable fair values are permitted to be measured at cost, less any impairment, plus or minus any changes resulting from observable price changes for identical or similar investments of the same issuer (the “measurement alternative”). The Company adopted these ASUs as of January 1, 2018, which was applicable to the Company on a prospective basis for its equity investments as they do not have readily determinable fair values, and for which the Company elected to utilize the measurement alternative. The adoption of these ASUs will result in volatility in other income (expense), net, upon the occurrence of any observable price changes or impairments related to its equity investments. For further information pertaining to the Company’s equity investments, see Note 4 - Fair Value of Financial Instruments. The other provisions of these ASUs did not have a material effect on the Company’s consolidated financial statements. Other Recent Accounting Pronouncements In June 2018, the FASB issued ASU 2018-07, Compensation-Stock Compensation (Topic 718) - Improvements to Nonemployee Share-Based Payment Accounting (“ASU 2018-07”). ASU 2018-07 expands the guidance in Topic 718 to include share-based payments for goods and services to non-employees and generally aligns it with the guidance for share-based payments to employees. ASU 2018-07 is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the effect of this ASU on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) (“ASU 2016-02”), which was further clarified and amended in July 2018 by ASU 2018-10, Codification Improvements to Topic 842, Leases (“ASU 2018-10”) and ASU 2018-11, Leases (Topic 842): Targeted Improvements (“ASU 2018-11”). These ASUs provide revised guidance for lease accounting and related disclosure requirements, including a requirement for lessees to recognize right-of use assets and lease liabilities on the balance sheet for leases with durations greater than twelve months. These ASUs are effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. As issued, ASU 2016-02 required modified retrospective application for all leases existing as of, or entered into after, the beginning of the earliest comparative period presented in the consolidated financial statements, with certain practical expedients available. ASU 2018-11 simplifies the transition requirements by providing companies an option to initially apply the new lease requirements as of the date of adoption and recognize a cumulative effect adjustment to the opening balance of retained earnings in the period of adoption. Under this guidance, comparative periods would not need to be restated. The Company will adopt these ASUs as of January 1, 2019, and upon adoption, expects to utilize the package of practical expedients that allow entities to retain the classification of lease contracts existing as of the date of adoption. The Company is evaluating the transition alternatives as provided under ASU 2018-11. The Company is continuing to assess the potential effects of these ASUs, which have not yet been quantified, on its consolidated financial statements, business processes, systems and controls. The Company’s assessment, which it expects to substantially complete in the fourth quarter of 2018, includes an evaluation of its existing lease portfolio, a comparison of its historical accounting policies and practices to the new standard, and an evaluation of the effect of certain accounting policy elections. The Company expects to implement a new lease accounting and administration software solution in connection with the new standard. In addition, the Company is evaluating certain changes to its current business processes and internal controls to meet the reporting and disclosure requirements of the new standard. These ASUs are not expected to have a material effect on the amount of expense recognized in connection with the Company’s current leasing arrangements as compared to current practice, however, based on the Company’s preliminary review of its lease contracts to date, it anticipates that it will recognize incremental lease assets and liabilities on its consolidated balance sheets upon adoption of the standard, and that the amount of such incremental lease assets and lease liabilities will be material. The Company’s expectations may change as its assessment progresses. For information about the Company’s future lease commitments as of December 31, 2017, see Note 8 - Lease Obligations, in the Company’s 2017 Form 10-K.

Earnings Per Share

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Earnings Per Share

Note 2 – Earnings Per Share

Basic earnings or loss per share is computed by dividing net income or loss attributable to MasTec by the weighted average number of common shares outstanding for the period, which excludes non-participating unvested restricted share awards. Diluted earnings per share is computed by dividing net income or loss attributable to MasTec by the weighted average number of fully diluted shares, as calculated under the treasury stock method, which includes the potential effect of dilutive common stock equivalents, such as issued but unvested restricted shares. If the Company reports a loss, rather than income, the computation of diluted loss per share excludes the effect of dilutive common stock equivalents, as their effect would be anti-dilutive.

The following table provides details underlying the Company’s earnings per share calculations for the periods indicated (in thousands):



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2018		2017		2018		2017
Net income attributable to MasTec:
Net income - basic and diluted ^(a)	$	80,492	$	81,668	$	107,052	$	122,638
Weighted average shares outstanding:
Weighted average shares outstanding - basic	78,984		80,925		80,061		80,812
Dilutive common stock equivalents	1,078		1,367		1,075		1,414
Weighted average shares outstanding - diluted	80,062		82,292		81,136		82,226

Additional information:
Weighted average anti-dilutive common stock equivalents ^(b)	—		13		—		6


(a)	Calculated as total net income less amounts attributable to non-controlling interests.


(b)	Represents anti-dilutive common stock equivalents as calculated under the treasury stock method.

The Company repurchased approximately 0.7 million and 2.7 million shares of its common stock during the three and six month periods ended June 30, 2018, respectively, as discussed in Note 11 - Equity. Current year share repurchases reduced the Company’s weighted average shares outstanding by 2.5 million shares for the three month period ended June 30, 2018, and by 1.4 million shares for the six month period ended June 30, 2018 as compared with the respective prior year periods.

Goodwill and Other Intangible Assets

6 Months Ended

Jun. 30, 2018

Goodwill and Other Intangible Assets

Note 3 – Goodwill and Other Intangible Assets

The following table provides balances for goodwill by reportable segment as of June 30, 2018 (in millions):



	Communications		Oil and Gas			Electrical Transmission		Power Generation and Industrial		Total Goodwill
Goodwill, gross	$	467.8	$	458.1		$	149.9	$	142.4	$	1,218.2
Accumulated impairment loss	—		(71.6		)	—		—		(71.6		)
Goodwill, net	$	467.8	$	386.5		$	149.9	$	142.4	$	1,146.6

For the six month period ended June 30, 2018, goodwill included additions of $9.8 million from new business combinations and a net increase of $1.6 million from measurement period adjustments. The net measurement period adjustment consisted primarily of adjustments related to deferred tax liabilities, estimated earn-out liabilities and other purchase price adjustments. For the six month period ended June 30, 2018, currency translation effects related to goodwill and accumulated impairment losses totaled approximately $5.8 million of losses and $3.2 million of gains, respectively.

The following table provides a reconciliation of changes in other intangible assets, net, for the period indicated (in millions):



	Other Intangible Assets
	Non-Amortizing					Amortizing
	Trade Names		Pre-Qualifications			Customer Relationships and Backlog			Other ^(a)			Total
Other intangible assets, gross, as of December 31, 2017	$	34.5	$	77.6		$	223.0		$	21.8		$	356.9
Accumulated amortization						(152.4		)	(13.4		)	(165.8		)
Other intangible assets, net, as of December 31, 2017	$	34.5	$	77.6		$	70.6		$	8.4		$	191.1
Additions from new business combinations	—		—			2.9			0.3			3.2
Measurement period adjustments ^(b)	—		—			0.4			(0.7		)	(0.3		)
Amortization expense						(9.5		)	(0.8		)	(10.3		)
Currency translation adjustments	—		(2.0		)	(0.2		)	—			(2.2		)
Other intangible assets, net, as of June 30, 2018	$	34.5	$	75.6		$	64.2		$	7.2		$	181.5


(a)	Consists principally of trade names and non-compete agreements.


(b)	Represents adjustments to preliminary estimates of the fair values of intangible assets acquired within the measurement period for the Company’s 2017 acquisitions.

Amortization expense associated with intangible assets for the three month periods ended June 30, 2018 and 2017 totaled $5.4 million and $4.9 million, respectively, and for the six month periods ended June 30, 2018 and 2017, totaled $10.3 million and $9.0 million, respectively.

2018 Acquisitions. During the first quarter of 2018, MasTec acquired all of the equity interests in a construction management firm specializing in steel building systems and acquired a wind turbine services company, both of which are included in the Company’s Power Generation and Industrial segment. The aggregate purchase price for these entities was composed of approximately $6.8 million in cash and estimated earn-out liabilities totaling $0.8 million as of June 30, 2018. Determination of the estimated fair values of the net assets acquired and the estimated earn-out liabilities for these acquisitions was preliminary as of June 30, 2018; as a result, further adjustments to these estimates may occur.

2017 Acquisitions. During 2017, MasTec completed three acquisitions, which included all of the equity interests in: (i) a wireline/fiber deployment construction contractor, which is included in the Company’s Communications segment; (ii) a heavy civil construction services company, which is included in the Company’s Power Generation and Industrial segment, and (iii) an oil and gas pipeline equipment company, which is included in the Company’s Oil and Gas segment. Determination of the estimated fair values of the net assets acquired and the estimated earn-out liabilities for certain of these acquisitions was preliminary as of June 30, 2018; as a result, further adjustments to these estimates may occur.

The following table summarizes the estimated fair values of consideration paid and net assets acquired as of the respective dates of acquisition, as adjusted (in millions):



Acquisition consideration:	2017
Cash	$	120.4
Fair value of contingent consideration (earn-out liability)	96.3
Total consideration transferred	$	216.7
Identifiable assets acquired and liabilities assumed:
Current assets, primarily composed of accounts receivable and $2.8 million of cash acquired	$	43.8
Property and equipment and other long-term assets	57.2
Amortizing intangible assets	28.1
Current liabilities, including current portion of capital lease obligations and long-term debt	(29.5		)
Long-term debt, including capital lease obligations	(9.9		)
Deferred income taxes and other long-term liabilities	(12.0		)
Total identifiable net assets	$	77.7
Goodwill	$	139.0
Total net assets acquired, including goodwill	$	216.7

Amortizing intangible assets related to the 2017 acquisitions are primarily composed of customer relationships, backlog and certain other intangible assets, which had weighted average lives, as adjusted, of approximately 11 years, 4 years and 6 years, respectively, and a weighted average life of 10 years in total. Amortizing intangible assets are amortized in a manner consistent with the pattern in which the related benefits are expected to be consumed. The goodwill balances for the respective acquisitions represent the estimated value of each acquired company’s geographic presence in key markets, its assembled workforce and management team industry-specific project management expertise, as well as synergies expected to be achieved from the combined operations of the acquired companies and MasTec. Approximately $92 million of the acquired goodwill balance as of June 30, 2018 is expected to be tax deductible.

The contingent consideration included in the table above equals a portion of the acquired companies’ earnings before interest, taxes, depreciation and amortization (“EBITDA”), in certain cases in excess of thresholds agreed upon with the sellers, if applicable, for a period of five years, as set forth in the respective purchase agreements, which amounts are payable annually. The fair values of the earn-out liabilities were estimated using income approaches such as discounted cash flows or option pricing models and incorporate significant inputs not observable in the market. Key assumptions in the estimated valuations include the discount rate and probability-weighted EBITDA projections. Significant changes in any of these assumptions could result in a significantly higher or lower potential earn-out liability. As of June 30, 2018, the range of remaining potential undiscounted earn-out liabilities for the 2017 acquisitions was estimated to be between $10 million and $161 million; however, there is no maximum payment amount.

For the three month periods ended June 30, 2018 and 2017, unaudited supplemental pro forma revenue totaled approximately $1,617.4 million and $1,924.0 million, respectively, and unaudited supplemental pro forma net income totaled approximately $80.6 million and $84.7 million, respectively. For the six month periods ended June 30, 2018 and 2017, unaudited supplemental pro forma revenue totaled approximately $3,017.7 million and $3,144.2 million, respectively, and unaudited supplemental pro forma net income totaled approximately $104.7 million and $127.1 million, respectively. These unaudited pro forma financial results represent the results of operations of the companies acquired as if the acquired companies had been consolidated as of the beginning of the year prior to their acquisition, and are provided for illustrative purposes only. These unaudited pro forma financial results do not purport to be indicative of the actual results that would have been achieved by the combined companies for the periods indicated, or of the results that may be achieved by the combined companies in the future. The Company’s unaudited pro forma financial results were prepared by adjusting the historical results of MasTec to include the historical results of the acquired businesses described above, and then adjusted for (i) acquisition costs; (ii) amortization expense resulting from the acquired intangible assets; (iii) interest expense as a result of the cash consideration paid; (iv) interest expense from debt repaid upon acquisition; and (iv) elimination of the effects of intercompany transactions and other purchase accounting related adjustments. These unaudited pro forma financial results do not include adjustments to reflect other cost savings or synergies that may have resulted from these acquisitions. Future results may vary significantly due to future events and transactions, as well as other factors, many of which are beyond the Company’s control.

For the three and six month periods ended June 30, 2018, the Company’s consolidated results of operations included acquisition-related revenue of approximately $45.7 million and $122.6 million, respectively, and acquisition-related net income of approximately $0.5 million and $2.5 million, respectively, based on the Company’s consolidated effective tax rate. For both the three and six month periods ended June 30, 2017, the Company’s consolidated results of operations included acquisition-related revenue of approximately $33.9 million and acquisition-related net income of approximately $1.6 million, based on the Company’s consolidated effective tax rate. These acquisition-related results do not include the effects of acquisition costs or interest expense associated with consideration paid for the related acquisitions.

Fair Value of Financial Instruments	6 Months Ended
Fair Value of Financial Instruments	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Note 4 – Fair Value of Financial Instruments The Company’s financial instruments include cash and cash equivalents, accounts and notes receivable, equity investments, life insurance assets, cash collateral deposited with insurance carriers, deferred compensation plan assets and liabilities, accounts payable and other current liabilities, acquisition-related contingent consideration and debt obligations. Fair value is the price that would be received to sell an asset or the amount paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value guidance establishes a valuation hierarchy, which requires maximizing the use of observable inputs when measuring fair value. The three levels of inputs that may be used are: (i) Level 1 - quoted market prices in active markets for identical assets or liabilities; (ii) Level 2 - observable market-based inputs or other observable inputs; and (iii) Level 3 - significant unobservable inputs that cannot be corroborated by observable market data, which are generally determined using valuation models incorporating management estimates of market participant assumptions. In instances in which the inputs used to measure fair value fall into different levels of the fair value hierarchy, the fair value measurement classification is determined based on the lowest level input that is significant to the fair value measurement in its entirety. Management’s assessment of the significance of a particular item to the fair value measurement in its entirety requires judgment, including the consideration of inputs specific to the asset or liability. Fair values of financial instruments are estimated using public market prices, quotes from financial institutions and other available information. Due to their short-term maturity, the carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and other current liabilities approximate their fair values. Management believes the carrying values of notes and other receivables, cash collateral deposited with insurance carriers and outstanding balances on its credit facilities approximate their fair values. Acquisition-Related Contingent Consideration Acquisition-related contingent consideration, or “earn-out” liabilities, represent the estimated fair value of future amounts payable for acquisitions of businesses and other interests. Acquisition-related contingent consideration is based on management estimates and entity-specific assumptions, which are Level 3 inputs, and are evaluated on an ongoing basis. As of June 30, 2018 and December 31, 2017, the estimated fair value of the Company’s earn-out liabilities totaled $102.0 million and $117.2 million, respectively, of which $26.0 million and $22.6 million, respectively, was included within other current liabilities. The fair value of the Company’s earn-out liabilities is estimated using income approaches such as discounted cash flows or option pricing models and incorporates significant inputs not observable in the market. Key assumptions include the discount rate and probability-weighted EBITDA projections. Significant changes in any of these assumptions could result in a significantly higher or lower potential earn-out liability. As of June 30, 2018, the range of potential undiscounted earn-out liabilities was estimated to be between $16 million and $171 million; however, there is no maximum payment amount. Acquisition-related contingent consideration activity consists primarily of additions from new business combinations and acquisitions of other interests; payments; and changes in the expected fair value of future earn-out obligations. Fair value adjustments for earn-out liabilities that relate to circumstances that developed after the date of acquisition are recorded within other income or expense, as appropriate. Fair value adjustments for earn-out liabilities that relate to new information obtained about the facts and circumstances that existed as of the date of acquisition, which are referred to as measurement period adjustments, are recorded to goodwill. There were no additions to acquisition-related contingent consideration from new business combinations for the three month period ended June 30, 2018, and additions for the six month period ended June 30, 2018 totaled approximately $1.5 million. For both the three and six month periods ended June 30, 2017, additions to acquisition-related contingent consideration from new business combinations totaled approximately $25.0 million. For the three month period ended June 30, 2018, measurement period adjustments for acquisition-related contingent consideration totaled a reduction of approximately $0.7 million, and for the six month period ended June 30, 2018, totaled a net increase of approximately $2.0 million, and related to businesses in the Company’s Oil and Gas and Power Generation and Industrial segments. Fair value adjustments for acquisition-related contingent consideration, including those related to finalization of completed earn-out arrangements, totaled net increases of approximately $4.4 million for both the three and six month periods ended June 30, 2018, primarily for businesses in the Company’s Communications and Oil and Gas segments, and a net decrease of approximately $8.6 million for both the three and six month periods ended June 30, 2017 for a business in the Company’s Communications segment. Payments of acquisition-related contingent consideration totaled $23.1 million for both the three and six month periods ended June 30, 2018, and totaled $18.8 million for both the three and six month periods ended June 30, 2017. Equity Investments The Company’s equity investments as of June 30, 2018 include: (i) the Company’s 33% equity interests in Trans-Pecos Pipeline, LLC (“TPP”) and Comanche Trail Pipeline, LLC (“CTP,” and together with TPP, the “Waha JVs”), which are accounted for as equity method investments; (ii) a $15 million investment in Cross Country Infrastructure Services, Inc. (“CCI”); (iii) the Company’s interests in certain proportionately consolidated non-controlled contractual joint ventures; (iv) the Company’s equity interests in Pensare Acquisition Corp. (“Pensare”); and (v) certain other equity investments. See Note 15 - Related Party Transactions for additional information related to certain of the Company’s equity investments. The fair values of the Company’s equity investments are not readily determinable. The Company’s equity investments, other than those that are proportionately consolidated, or those accounted for as equity method investments or under the fair value option, are measured at cost, adjusted for changes from observable market transactions, less impairment (“adjusted cost basis”). Realized and unrealized fair market value gains or losses related to the Company’s equity investments are recognized in other income or expense. Fair value measurements for the Company’s equity investments are classified within Level 3 in the fair value hierarchy based on the nature of the fair value inputs. For the six month period ended June 30, 2018, the Company was not aware of any material observable market transactions related to, or impairments of, its equity investments measured on an adjusted cost basis. The aggregate carrying value of the Company’s equity investments as of June 30, 2018 and December 31, 2017 totaled approximately $190 million and $141 million, respectively, including approximately $18 million of equity investments measured on an adjusted cost basis for both periods. The Waha JVs. The Waha JVs own and operate two pipelines and a header system that transport natural gas to the Mexican border for export, for which operations commenced in 2017. For the three month periods ended June 30, 2018 and 2017, the Company made equity contributions to these joint ventures of approximately $9.7 million and $19.9 million, respectively, and for the six month periods ended June 30, 2018 and 2017, made equity contributions totaling $24.5 million and $73.3 million, respectively. The Company previously issued letters of credit in connection with its equity commitments in the Waha JVs. As of June 30, 2018, there were no letters of credit remaining, and as of December 31, 2017, $19 million in letters of credit were outstanding. Equity in earnings related to the Company’s proportionate share of income from the Waha JVs, which is included within the Company’s Other segment, totaled approximately $5.8 million and $6.1 million for the three month periods ended June 30, 2018 and 2017, respectively, and totaled $11.4 million and $7.7 million for the six month periods ended June 30, 2018 and 2017, respectively. Cumulative undistributed earnings from the Waha JVs totaled $20.6 million as of June 30, 2018. For the three and six month periods ended June 30, 2018, the Company received $2.0 million and $7.7 million, respectively, in distributions of earnings from the Waha JVs, which amounts are included within operating cash flows. The Company’s net investment in the Waha JVs, which differs from its proportionate share of the net assets of the Waha JVs, due primarily to capitalized investment costs, totaled approximately $160 million and $121 million as of June 30, 2018 and December 31, 2017, respectively. Certain subsidiaries of MasTec have provided pipeline construction services to the Waha JVs. Revenue recognized in connection with work performed for the Waha JVs, including intercompany eliminations, totaled $100.2 million and $251.6 million for the three and six month periods ended June 30, 2017, respectively, and for the three and six month periods ended June 30, 2018, was de minimis. As of June 30, 2018 and December 31, 2017, related receivables, net of billings in excess of costs and earnings, totaled $0.2 million and $2.8 million, respectively. TPP and CTP are party to separate non-recourse financing facilities, each of which are secured by pledges of the equity interests in the respective entities, as well as a first lien security interest over virtually all of TPP’s and CTP’s assets. The Waha JVs are also party to certain interest rate swaps, which are accounted for as qualifying cash flow hedges. The Company reflects its proportionate share of any unrealized fair market value gains or losses from fluctuations in interest rates associated with these swaps within other comprehensive income or loss, as appropriate. For the three and six month periods ended June 30, 2018, the Company’s proportionate share of unrecognized unrealized activity on these interest rate swaps was a gain of approximately $3.9 million and $14.0 million, respectively, or $2.9 million and $10.7 million, net of tax, respectively. For the three and six month periods ended June 30, 2017, the Company’s proportionate share of unrecognized unrealized activity on these interest rate swaps was a loss of approximately $4.4 million and $3.4 million, respectively, or $2.7 million and $2.1 million, net of tax, respectively. Other Investments. During the third quarter of 2017, the Company paid $2.0 million for approximately 4% of the common stock of Pensare and warrants to purchase 2.0 million shares of Pensare common stock, which is a special purpose acquisition company focusing on transactions in the telecommunications industry. The shares of common stock purchased by MasTec are not transferable or salable until one year after Pensare successfully completes a business combination transaction, with limited exceptions, as specified in the agreement. The warrants purchased by MasTec are exercisable at a purchase price of $11.50 per share after Pensare successfully completes a business combination. Both the warrants and shares expire and/or are effectively forfeitable if Pensare does not successfully complete a business combination by February 1, 2019. The warrants, which are derivative financial instruments, and the shares, which are measured on an adjusted cost basis, are included within other long-term assets in the Company’s consolidated financial statements as of June 30, 2018. The warrants approximated their initial cost basis as of June 30, 2018, as determined based on Level 3 inputs. Due to the nature of the restrictions, the fair value of the shares is not readily determinable, and there were no observable price changes for similar investments during either of the three or six month periods ended June 30, 2018. José R. Mas, MasTec’s Chief Executive Officer, is a director of Pensare. During the second quarter of 2018, the Company invested $10.0 million for a 38.5% interest in LifeShield, LLC (“LifeShield”), a home security company, which is measured under the fair value option. Management believes that the fair value option provides a more accurate reflection of the economic performance of LifeShield and the value of the Company’s equity interest in the business. As of June 30, 2018, the fair value of this investment approximated its purchase price. In connection with the 2014 acquisition of Pacer Construction Holdings Corporation and its affiliated operating companies (collectively, “Pacer”), the Company acquired an investment, for which the Company now has minimal involvement, that is in the final stages of being liquidated and is being managed by a receiver. The Company regularly reviews this investment for potential changes in expected recovery estimates, and during the second quarter of 2018, recorded $0.9 million of expense related to changes in expected recovery estimates, and during the second quarter of 2017, recorded $5.8 million of expense. The Company received $5.4 million of proceeds from the receiver in the first quarter of 2018, and received $12.1 million of proceeds in the first quarter of 2017. The net carrying value of this asset, which is included within other current assets, totaled $3.0 million and $9.6 million as of June 30, 2018 and December 31, 2017, respectively. Senior Notes As of both June 30, 2018 and December 31, 2017, the gross carrying amount of the Company’s 4.875% senior notes due March 15, 2023 (the “4.875% Senior Notes”), which are measured at fair value on a non-recurring basis, totaled $400 million. As of June 30, 2018 and December 31, 2017, the estimated fair value of the 4.875% Senior Notes, based on Level 1 inputs, totaled $392.0 million and $410.0 million, respectively.

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities

6 Months Ended

Jun. 30, 2018

Receivables [Abstract]

Note 5 – Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities

The following table provides details of accounts receivable, net of allowance and contract assets (together, “accounts receivable, net”) as of the dates indicated (in millions):



	June 30, 2018			December 31, 2017
Contract billings	$	561.6		$	683.9
Less allowance for doubtful accounts	(9.5		)	(8.2		)
Accounts receivable, net of allowance	$	552.1		$	675.7
Retainage	317.9			323.1
Costs and earnings in excess of billings	1,207.5			599.2
Retainage and costs and earnings in excess of billings (together, “contract assets”)	$	1,525.4		$	922.3
Accounts receivable, net	$	2,077.5		$	1,598.0

Contract billings represent the amount of performance obligations that have been billed but not yet collected. Contract assets consist of costs and earnings in excess of billings (“CIEB”) and retainage. CIEB, which is also referred to as work in process, represents the estimated value of unbilled work for projects with performance obligations recognized over time. Retainage represents a portion of the contract amount that has been billed, but for which the contract allows the customer to retain a portion of the billed amount until final contract settlement (generally, from 5% to 10% of contract billings). Retainage is not considered to be a significant financing component because the intent is to protect the customer. CIEB and retainage amounts are generally classified as current assets within the Company’s consolidated balance sheets. Impairment losses on contract assets were not material for the three and six month periods ended June 30, 2018.

Under certain contracts, the Company may be entitled to invoice the customer in advance of performing the related contract work. In those instances, the Company recognizes a liability for advance billings in excess of revenue recognized, which is referred to as billings in excess of costs and earnings (“BIEC”). BIEC is not considered to be a significant financing component because it is generally used to meet working capital demands that can be higher in the early stages of a contract. Contract liabilities consist primarily of such BIEC, which are generally classified within current liabilities on the Company’s consolidated balance sheets. BIEC totaled approximately $243.2 million and $194.5 million as of June 30, 2018 and December 31, 2017, respectively. For the three and six month periods ended June 30, 2018, the Company recognized revenue of approximately $15.0 million and $99.8 million, respectively, related to amounts that were included in BIEC as of December 31, 2017, resulting primarily from the advancement of physical progress on the respective projects during the period. Contract liabilities also include the amount of any accrued project losses, which are classified within other current liabilities on the Company’s consolidated balance sheets. Total contract liabilities, including accrued project losses, totaled approximately $251.1 million and $206.1 million as of June 30, 2018 and December 31, 2017, respectively.

Provisions for doubtful accounts for each of the three month periods ended June 30, 2018 and 2017 totaled $0.5 million and $0.2 million, respectively, and for the six month periods ended June 30, 2018 and 2017, totaled $1.4 million and $0.7 million, respectively. Retainage, which has been billed, but is not due until completion of performance and acceptance by customers, is expected to be collected within one year. Accounts receivable expected to be collected beyond one year are recorded within other long-term assets. The increase in the CIEB balance for the six month period ended June 30, 2018 was driven largely by long-haul project activity and timing of billings within the Company’s Oil and Gas segment.

The Company is party to non-recourse financing arrangements in the ordinary course of business, under which certain receivables are settled with the customer’s bank in return for a nominal fee. These arrangements, under which amounts can vary based on levels of activity, interest rates and changes in customer payment terms, improve the collection cycle time of the related receivables. Cash collected from these arrangements is reflected within cash provided by operating activities in the consolidated statements of cash flows. The discount charge, which is included within interest expense, net, totaled approximately $3.1 million and $1.7 million for the three month periods ended June 30, 2018 and 2017, respectively, and totaled approximately $5.0 million and $2.6 million for the six month periods ended June 30, 2018 and 2017, respectively.

Property, Plant and Equipment [Abstract]

The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.

+ References + Details

Property and Equipment, Net

6 Months Ended

Jun. 30, 2018

Property and Equipment, Net

Note 6 – Property and Equipment, Net

The following table provides details of property and equipment, net, including property and equipment held under capital leases as of the dates indicated (in millions):



	June 30, 2018			December 31, 2017
Land	$	4.6		$	4.6
Buildings and leasehold improvements	28.4			26.7
Machinery and equipment	1,319.5			1,261.9
Office furniture and equipment	157.3			149.9
Construction in progress	26.2			12.5
Total property and equipment	$	1,536.0		$	1,455.6
Less accumulated depreciation and amortization	(796.6		)	(749.1		)
Property and equipment, net	$	739.4		$	706.5

The gross amount of capitalized internal-use software, which is included within office furniture and equipment, totaled $115.8 million and $109.9 million as of June 30, 2018 and December 31, 2017, respectively. Capitalized internal-use software, net of accumulated amortization, totaled $25.0 million and $23.5 million as of June 30, 2018 and December 31, 2017, respectively. Depreciation and amortization expense associated with property and equipment for the three month periods ended June 30, 2018 and 2017 totaled $46.3 million and $40.5 million, respectively, and totaled $91.3 million and $79.2 million for the six month periods ended June 30, 2018 and 2017, respectively.

Debt

6 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Debt

Note 7 – Debt

The following table provides details of the carrying values of debt as of the dates indicated (in millions):



Description	Maturity Date	June 30, 2018			December 31, 2017
Senior secured credit facility:	February 22, 2022
Revolving loans		$	648.1		$	377.7
Term loan		386.9			396.9
4.875% Senior Notes	March 15, 2023	400.0			400.0
Capital lease obligations, weighted average interest rate of 3.8%	In installments through May 1, 2023	182.6			181.2
Other debt obligations	Varies	11.1			25.8
Total long-term debt obligations		$	1,628.7		$	1,381.6
Less unamortized deferred financing costs		(11.5		)	(13.0		)
Total debt, net of deferred financing costs		$	1,617.2		$	1,368.6
Current portion of long-term debt		84.2			87.9
Long-term debt		$	1,533.0		$	1,280.7

Senior Secured Credit Facility

The Company has a senior secured credit facility (the “Credit Facility”). Under the Credit Facility, aggregate borrowing commitments totaled approximately $1.5 billion as of June 30, 2018, composed of $1.1 billion of revolving commitments and a term loan of approximately $0.4 billion. The term loan is subject to amortization in quarterly principal installments. An initial installment of $3.1 million was paid in December 2017, and quarterly installments of $5.0 million commenced in the first quarter of 2018. Quarterly principal installments on the term loan are subject to adjustment, if applicable, for certain prepayments.

As of June 30, 2018 and December 31, 2017, outstanding revolving loans, which included $106 million and $117 million, respectively, of borrowings denominated in foreign currencies, accrued interest at weighted average rates of approximately 3.91% and 3.69% per annum, respectively. The term loan accrued interest at a rate of 3.72% and 3.07% as of June 30, 2018 and December 31, 2017, respectively. Letters of credit of approximately $124.7 million and $157.1 million were issued as of June 30, 2018 and December 31, 2017, respectively. As of June 30, 2018 and December 31, 2017, letters of credit fees accrued at 0.750% and 0.625% per annum, respectively, for performance standby letters of credit, and at 1.625% and 1.50% per annum, respectively, for financial standby letters of credit. Outstanding letters of credit mature at various dates and most have automatic renewal provisions, subject to prior notice of cancellation. As of June 30, 2018 and December 31, 2017, availability for revolving loans totaled $327.2 million and $565.2 million, respectively, or up to $327.2 million and $492.9 million, respectively, for new letters of credit. Revolving loan borrowing capacity included $194.4 million and $183.4 million of availability in either Canadian dollars or Mexican pesos as of June 30, 2018 and December 31, 2017, respectively. The unused facility fee as of June 30, 2018 and December 31, 2017 accrued at a rate of 0.30% and 0.25%, respectively.

The Credit Facility is guaranteed by certain subsidiaries of the Company (the “Guarantor Subsidiaries”) and the obligations under the Credit Facility are secured by substantially all of the Company’s and the Guarantor Subsidiaries’ respective assets, subject to certain exceptions.

Other Credit Facilities. The Company has other credit facilities that support the working capital requirements of its foreign operations. Borrowings under these credit facilities, which have varying dates of maturity and are generally renewed on an annual basis, are denominated in Canadian dollars. As of both June 30, 2018 and December 31, 2017, maximum borrowing capacity totaled Canadian $20.0 million, or approximately $15.2 million and $15.9 million, respectively. As of June 30, 2018 and December 31, 2017, outstanding borrowings totaled approximately $9.2 million and $10.4 million, respectively, and accrued interest at a weighted average rate of approximately 4.2% and 4.0%, respectively. Outstanding borrowings that are not renewed are repaid with borrowings under the Credit Facility. Accordingly, the carrying amounts of the Company’s borrowings under its other credit facilities, which are included within other debt obligations in the table above, are classified within long-term debt in the Company’s consolidated balance sheets. The Company’s other credit facilities are subject to customary provisions and covenants.

Debt Guarantees and Covenants

The 4.875% Senior Notes are senior unsecured unsubordinated obligations and rank equal in right of payment with existing and future unsubordinated debt, and rank senior in right of payment to existing and future subordinated debt and are fully and unconditionally guaranteed on an unsecured, unsubordinated, joint and several basis by certain of the Company’s existing and future 100%-owned direct and indirect domestic subsidiaries that are each guarantors of the Credit Facility or other outstanding indebtedness. See Note 16 - Supplemental Guarantor Condensed Unaudited Consolidating Financial Information.

MasTec was in compliance with the provisions and covenants of its outstanding debt instruments as of June 30, 2018 and December 31, 2017.

Additional Information

As of June 30, 2018 and December 31, 2017, accrued interest payable, which is recorded within other accrued expenses in the consolidated balance sheets, totaled $8.2 million and $7.4 million, respectively. For additional information pertaining to the Company’s debt instruments, including its 4.875% Senior Notes, see Note 7 - Debt in the Company’s 2017 Form 10-K.

Lease Obligations	6 Months Ended
Lease Obligations	Jun. 30, 2018
Leases [Abstract]
Lease Obligations	Note 8 – Lease Obligations Capital Leases MasTec enters into agreements that provide lease financing for machinery and equipment. The gross amount of assets held under capital leases as of June 30, 2018 and December 31, 2017, which are included within property and equipment, net, totaled $432.4 million and $418.0 million, respectively. Assets held under capital leases, net of accumulated depreciation, totaled $287.4 million and $277.3 million as of June 30, 2018 and December 31, 2017, respectively. Operating Leases In the ordinary course of business, the Company enters into non-cancelable operating leases for certain of its facility, vehicle and equipment needs, including related party leases. See Note 15 - Related Party Transactions. Rent and related expense for operating leases that have non-cancelable terms in excess of one year totaled approximately $25.3 million and $26.6 million for the three month periods ended June 30, 2018 and 2017, respectively, and totaled $52.2 million for both the six month periods ended June 30, 2018 and 2017. The Company also incurred rent and related expense for facilities, vehicles and equipment having original terms of one year or less totaling approximately $104.9 million and $133.3 million for the three month periods ended June 30, 2018 and 2017, respectively, and totaling $196.6 million and $188.4 million for the six month periods ended June 30, 2018 and 2017, respectively.

Stock-Based Compensation and Other Employee Benefit Plans

6 Months Ended

Jun. 30, 2018

Share-based Compensation [Abstract]

Stock-Based Compensation and Other Employee Benefit Plans

Note 9 – Stock-Based Compensation and Other Employee Benefit Plans

The Company has stock-based compensation plans, under which shares of the Company’s common stock are reserved for issuance. Under all stock-based compensation plans in effect as of June 30, 2018, including employee stock purchase plans, there were approximately 4,675,000 shares available for future grant.

Restricted Shares

MasTec grants restricted stock awards and restricted stock units (together “restricted shares”) to eligible employees and directors, which are valued based on the closing market share price of MasTec common stock (the “market price”) on the date of grant. During the restriction period, holders of restricted stock awards are entitled to vote the shares. Total unearned compensation related to restricted shares as of June 30, 2018 was approximately $19.7 million, which is expected to be recognized over a weighted average period of approximately 2.0 years. The intrinsic value of restricted shares that vested, which is based on the market price on the date of vesting, totaled $1.6 million and $0.2 million for the three month periods ended June 30, 2018 and 2017, respectively, and totaled $1.7 million and $11.7 million for the six month periods ended June 30, 2018 and 2017, respectively.



Activity, restricted shares: ^(a)	Restricted Shares		Per Share Weighted Average Grant Date Fair Value
Non-vested restricted shares, as of December 31, 2017	1,448,591		$	23.29
Granted	116,822		50.67
Vested	(36,477	)	21.85
Canceled/forfeited	(29,054	)	20.65
Non-vested restricted shares, as of June 30, 2018	1,499,882		$	25.51


(a)	Includes 19,300 and 27,550 restricted stock units as of June 30, 2018 and December 31, 2017, respectively.

Employee Stock Purchase Plans

The Company has certain employee stock purchase plans (collectively, “ESPPs”) under which shares of the Company's common stock are available for purchase by eligible employees. The following table provides details pertaining to the Company’s ESPPs for the periods indicated:



	For the Six Months Ended June 30,
	2018		2017
Cash proceeds (in millions)	$	2.2	$	1.6
Common shares issued	55,138		49,502
Weighted average price per share	$	39.99	$	33.30
Weighted average per share grant date fair value	$	9.74	$	8.67

Non-Cash Stock-Based Compensation Expense

Details of non-cash stock-based compensation expense and related tax effects for the periods indicated were as follows (in millions):



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2018		2017		2018		2017
Non-cash stock-based compensation expense	$	3.4	$	3.4	$	6.6	$	7.2
Income Tax Effects:
Income tax effect of non-cash stock-based compensation	$	1.0	$	1.3	$	1.8	$	2.5
Excess tax benefit from non-cash stock-based compensation ^(a)	$	0.2	$	0.0	$	0.2	$	0.1

(a)

Excess tax benefits represent cash flows from tax deductions in excess of the tax effect of compensation expense associated with share-based payment arrangements. For the six month period ended June 30, 2018, tax benefits, net of tax deficiencies, related to the vesting of share-based payment awards were $0.2 million, and for the six month period ended June 30, 2017, the Company recognized a tax deficiency, net of tax benefits, of $0.1 million.

Other Retirement Plans

6 Months Ended

Jun. 30, 2018

Multiemployer Plans [Abstract]

Other Retirement Plans

Note 10 – Other Retirement Plans

Multiemployer Plans. Certain of MasTec’s subsidiaries, including certain subsidiaries in Canada, contribute amounts to multiemployer pension and other multiemployer benefit plans and trusts (“MEPPs”), which are recorded as a component of employee wages and salaries within costs of revenue, excluding depreciation and amortization. Contributions are generally based on fixed amounts per hour per employee for employees covered under these plans. Multiemployer plan contribution rates are determined annually and assessed on a “pay-as-you-go” basis based on union employee payrolls. Union payrolls cannot be determined for future periods because the number of union employees employed at any given time, and the plans in which they participate, vary depending upon the location and number of ongoing projects at a given time and the need for union resources in connection with those projects. Total contributions to multiemployer plans and the related number of employees covered by these plans, including with respect to the Company’s Canadian operations, for the periods indicated were as follows:



	Multiemployer Plans
	Covered Employees		Contributions (in millions)
	Low	High	Pension		Other Multiemployer		Total
For the Three Months Ended June 30:
2018	2,612	6,183	$	19.7	$	2.1	$	21.8
2017	3,669	7,057	$	28.3	$	2.7	$	31.0
For the Six Months Ended June 30:
2018	2,018	6,183	$	31.0	$	4.1	$	35.1
2017	550	7,057	$	32.0	$	5.3	$	37.3

The fluctuations in the number of employees covered under multiemployer plans and related contributions in the table above related primarily to timing of activity for the Company’s union resource-based projects within its oil and gas operations.

Equity	6 Months Ended
Equity	Jun. 30, 2018
Equity [Abstract]
Equity	Note 11 – Equity Share Activity During the three and six month periods ended June 30, 2018, the Company repurchased approximately 0.7 million and 2.7 million shares of its common stock, respectively, for an aggregate purchase price of $29.9 million and $128.3 million, respectively. Of the total repurchased shares, 2.0 million were repurchased in the first quarter of 2018 for $98.4 million under a now completed share repurchase program that was established in 2016. The remaining 0.7 million shares were repurchased in the second quarter of 2018 under a new $100 million share repurchase program that was authorized by the Company’s Board of Directors in March 2018 (the “2018 Share Repurchase Program”), under which approximately $70 million is available as of June 30, 2018 for future share repurchases. Under the 2018 Share Repurchase Program, which does not have an expiration date, the Company may repurchase shares of its common stock from time to time in open market transactions or in privately-negotiated transactions in accordance with applicable securities laws. The timing and the amount of any repurchases will be determined based on market conditions, legal requirements, cash flow and liquidity needs and other factors. The share repurchase program may be modified or suspended at any time at the Company’s discretion. Share repurchases, which are recorded at cost and are held in the Company’s treasury, are funded with available cash or with availability under the Credit Facility. Accumulated Other Comprehensive Loss Accumulated other comprehensive loss is composed of unrealized foreign currency gains and losses from fluctuations in foreign currency exchange rates of the Company’s foreign subsidiaries with a functional currency other than the U.S. dollar, as well as unrealized gains and losses from certain investment activities. Unrealized foreign currency activity for each of the three and six month periods ended June 30, 2018 and 2017 is primarily related to translation gains and losses resulting from the Company’s Canadian operations, and unrealized investment activity for each of the three and six month periods ended June 30, 2018 and 2017 relates to unrealized gains and losses on interest rate swaps associated with the Waha JVs.

Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 12 – Income Taxes In determining the quarterly provision for income taxes, management uses an estimated annual effective tax rate based on forecasted annual pre-tax income, permanent tax differences, statutory tax rates and tax planning opportunities in the various jurisdictions in which the Company operates. The effect of significant discrete items is separately recognized in the quarter(s) in which they occur. In December 2017, the Tax Cuts and Jobs Act of 2017 (the “2017 Tax Act”) was enacted, which included broad tax reform that is applicable to the Company. Under the provisions of the 2017 Tax Act, the U.S. corporate tax rate decreased from 35% to 21% effective January 1, 2018. The Company completed an initial remeasurement of its U.S. deferred tax assets and liabilities as of December 31, 2017 as a result of this new tax law and recognized a non-cash tax benefit of $120.1 million in the fourth quarter of 2017. This initial remeasurement contained estimates of the effect of the 2017 Tax Act, as permitted under Staff Accounting Bulletin (“SAB”) 118, and may be affected by future guidance, finalization of its tax returns for the year ended December 31, 2017, and/or as a result of newly obtained information pertaining to its deferred tax balances as of December 31, 2017. In March 2018, the FASB issued ASU 2018-05, Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 (“ASU 2018-05”), which amended Topic 740 to incorporate the requirements of SAB 118. Any revisions to the initial remeasurement of the Company’s deferred tax assets and liabilities as of December 31, 2017 for the effects of the 2017 Tax Act will be treated in accordance with the measurement period guidance as outlined in Topic 740 and SAB 118. In the second quarter of 2018, the Company recognized tax expense of approximately $1.5 million related to an adjustment to the initial remeasurement of its deferred tax liabilities as a result of the 2017 Tax Act.

Segments and Related Information

6 Months Ended

Jun. 30, 2018

Segment Reporting [Abstract]

Segments and Related Information

Note 13 – Segments and Related Information

Segment Discussion

MasTec manages its operations under five operating segments, which represent MasTec’s five reportable segments: (1) Communications; (2) Oil and Gas; (3) Electrical Transmission; (4) Power Generation and Industrial and (5) Other. This structure is generally focused on broad end-user markets for MasTec’s labor-based construction services. All five reportable segments derive their revenue from the engineering, installation and maintenance of infrastructure, primarily in North America.

The Communications segment performs engineering, construction, maintenance and customer fulfillment activities related to communications infrastructure primarily for wireless and wireline/fiber communications and install-to-the-home customers, and, to a lesser extent, infrastructure for utilities, among others. MasTec performs engineering, construction and maintenance services on oil and natural gas pipelines and processing facilities for the energy and utilities industries through its Oil and Gas segment. The Electrical Transmission segment primarily serves the energy and utility industries through the engineering, construction and maintenance of electrical transmission lines and substations. The Power Generation and Industrial segment primarily serves energy, utility and other end-markets through the installation and construction of conventional and renewable power facilities, related electrical transmission infrastructure, ethanol/biofuel facilities and various types of heavy civil and industrial infrastructure. The Other segment includes equity investees, the services of which vary from those provided by the Company’s four primary segments, as well as other small business units that perform construction and other services for a variety of international end-markets.

Earnings before interest, taxes, depreciation and amortization (“EBITDA”) is the measure of profitability used by management to manage its segments and, accordingly, in its segment reporting. As appropriate, the Company supplements the reporting of consolidated financial information determined in accordance with U.S. GAAP with certain non-U.S. GAAP financial measures, including EBITDA. The Company believes these non-U.S. GAAP measures provide meaningful information and help investors understand the Company’s financial results and assess its prospects for future performance. The Company uses EBITDA to evaluate its performance, both internally and as compared with its peers, because it excludes certain items that may not be indicative of the Company’s core operating results for its reportable segments, as well as items that can vary widely across different industries or among companies within the same industry, and for non-cash stock-based compensation expense, can also be subject to volatility from changes in the market price per share of the Company’s common stock or variations in the value of shares granted. Segment EBITDA is calculated in a manner consistent with consolidated EBITDA.

For the six month period ended June 30, 2018, Other segment EBITDA included project gains of $1.0 million from a proportionately consolidated non-controlled Canadian joint venture, which is managed by a third party, and for which the Company has minimal direct construction involvement, whereas for the six month period ended June 30, 2017, Other segment EBITDA included project losses from this non-controlled joint venture of $7.0 million.

Summarized financial information for MasTec’s reportable segments is presented and reconciled to consolidated financial information for total MasTec in the following tables, including a reconciliation of consolidated income before income taxes to EBITDA (in millions). The tables below may contain slight summation differences due to rounding.



	For the Three Months Ended June 30,						For the Six Months Ended June 30,
Revenue:	2018			2017			2018			2017
Communications ^(a)	$	618.6		$	592.2		$	1,245.7		$	1,151.7
Oil and Gas	769.3			1,140.4			1,305.8			1,596.2
Electrical Transmission	84.5			96.6			198.5			195.4
Power Generation and Industrial	146.0			60.7			263.6			107.3
Other	0.2			1.9			2.2			3.6
Eliminations	(0.8		)	(1.6		)	(1.2		)	(5.8		)
Consolidated revenue	$	1,617.8		$	1,890.2		$	3,014.6		$	3,048.4


(a)	Revenue generated primarily by utilities customers represented 13.6% and 11.5% of Communications segment revenue for the three month periods ended June 30, 2018 and 2017, respectively, and represented 15.7% and 12.4% for the six month periods ended June 30, 2018 and 2017, respectively.



	For the Three Months Ended June 30,						For the Six Months Ended June 30,
EBITDA:	2018			2017			2018			2017
Communications	$	73.7		$	59.5		$	155.8		$	107.8
Oil and Gas	122.7			154.0			155.7			247.9
Electrical Transmission	(2.7		)	3.5			1.9			6.7
Power Generation and Industrial	9.8			4.7			14.6			5.6
Other	6.8			6.8			12.7			1.5
Corporate	(21.6		)	(29.6		)	(47.5		)	(47.1		)
Consolidated EBITDA	$	188.7		$	198.9		$	293.2		$	322.4



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
Depreciation and Amortization:	2018		2017		2018		2017
Communications	$	15.3	$	13.5	$	29.9	$	25.5
Oil and Gas	26.1		23.2		51.6		45.1
Electrical Transmission	5.1		5.7		10.4		11.4
Power Generation and Industrial	3.6		1.4		6.6		2.9
Other	0.0		0.0		0.1		0.1
Corporate	1.6		1.6		3.0		3.3
Consolidated depreciation and amortization	$	51.7	$	45.4	$	101.6	$	88.3



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
EBITDA Reconciliation:	2018		2017		2018		2017
Income before income taxes	$	116.2	$	138.8	$	153.8	$	206.8
Plus:
Interest expense, net	20.8		14.8		37.9		27.4
Depreciation and amortization	51.7		45.4		101.6		88.3
Consolidated EBITDA	$	188.7	$	198.9	$	293.2	$	322.4

Foreign Operations. MasTec operates in North America, primarily in the United States and Canada, and, to a lesser extent, in Mexico. For the three month periods ended June 30, 2018 and 2017, revenue of $1.6 billion and $1.8 billion, respectively, was derived from U.S. operations, and revenue of $26.7 million and $40.5 million, respectively, was derived from foreign operations, the majority of which was from the Company’s Canadian operations in the Oil and Gas segment. For the six month periods ended June 30, 2018 and 2017, revenue of $3.0 billion and $2.9 billion, respectively, was derived from U.S. operations, and revenue of $60.5 million and $99.7 million, respectively, was derived from foreign operations, the majority of which was from the Company’s Canadian operations in the Oil and Gas segment. Long-lived assets held in the U.S. included property and equipment, net, of $698.6 million and $649.5 million as of June 30, 2018 and December 31, 2017, respectively, and, for the Company’s businesses in foreign countries, the majority of which are in Canada, totaled $40.8 million and $57.0 million, respectively. Intangible assets and goodwill, net, related to the Company’s U.S. operations totaled approximately $1.2 billion as of both June 30, 2018 and December 31, 2017, and for the Company’s businesses in foreign countries, the majority of which are in Canada, totaled approximately $107.0 million and $112.8 million as of June 30, 2018 and December 31, 2017, respectively. As of June 30, 2018 and December 31, 2017, amounts due from customers from which foreign revenue was derived accounted for approximately 3% and 5%, respectively, of the Company’s consolidated net accounts receivable position, which represents accounts receivable, net, less BIEC.

Significant Customers

Revenue concentration information for significant customers as a percentage of total consolidated revenue was as follows:



	For the Three Months Ended June 30,		For the Six Months Ended June 30,
Customer:	2018	2017	2018	2017
AT&T (including DIRECTV^®) ^(a)	25%	22%	26%	27%
Energy Transfer affiliates ^(b)	15%	47%	20%	35%
EQT Corporation ^(c)	19%	—%	11%	—%

(a)

The Company’s relationship with AT&T is based upon multiple separate master service and other service agreements, including for installation and maintenance services, as well as construction/installation contracts for AT&T’s: (i) wireless business; (ii) wireline/fiber businesses; and (iii) various install-to-the-home businesses, including DIRECTV®. Revenue from AT&T is included in the Communications segment.


(b)	The Company's relationship with Energy Transfer affiliates is based upon various construction contracts for pipeline activities with Energy Transfer Partners L.P., and its subsidiaries and affiliates, all of which are consolidated by Energy Transfer Equity, L.P. Revenue from Energy Transfer affiliates is included in the Oil and Gas segment.


(c)	The Company's relationship with EQT Corporation and its affiliates is based upon various construction contracts for pipeline activities. Revenue from EQT Corporation is included in the Oil and Gas segment.

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 14 – Commitments and Contingencies MasTec is subject to a variety of legal cases, claims and other disputes that arise from time to time in the ordinary course of its business, including project contract price and acquisition purchase price disputes. MasTec cannot provide assurance that it will be successful in recovering all or any of the potential damages it has claimed or in defending claims against the Company. The outcome of such cases, claims and disputes cannot be predicted with certainty and an unfavorable resolution of one or more of them could have a material adverse effect on the Company’s business, financial condition, results of operations and cash flows. Other Commitments and Contingencies Leases. In the ordinary course of business, the Company enters into non-cancelable operating leases for certain of its facility, vehicle and equipment needs, including related party leases. See Note 8 - Lease Obligations and Note 15 - Related Party Transactions. Letters of Credit. In the ordinary course of business, the Company is required to post letters of credit for its insurance carriers, surety bond providers and in support of performance under certain contracts as well as certain obligations associated with the Company’s equity investments, including its variable interest entities. Such letters of credit are generally issued by a bank or similar financial institution. The letter of credit commits the issuer to pay specified amounts to the holder of the letter of credit under certain conditions. If this were to occur, the Company would be required to reimburse the issuer of the letter of credit, which, depending upon the circumstances, could result in a charge to earnings. As of June 30, 2018 and December 31, 2017, there were $124.7 million and $157.1 million, respectively, of letters of credit issued under the Company’s Credit Facility. The Company is not aware of any material claims relating to its outstanding letters of credit as of June 30, 2018 or December 31, 2017. Performance and Payment Bonds. In the ordinary course of business, MasTec is required by certain customers to provide performance and payment bonds for contractual commitments related to projects in process. These bonds provide a guarantee to the customer that the Company will perform under the terms of a contract and that the Company will pay subcontractors and vendors. If the Company fails to perform under a contract or to pay subcontractors and vendors, the customer may demand that the surety make payments or provide services under the bond. The Company must reimburse the surety for expenses or outlays it incurs. As of June 30, 2018 and December 31, 2017, outstanding performance and payment bonds totaled $108.6 million and $119.7 million, respectively, and estimated costs to complete projects secured by these bonds totaled $43.8 million and $46.0 million as of June 30, 2018 and December 31, 2017, respectively. These amounts do not include performance and payment bonds associated with the Company’s equity investments. Investment Arrangements. From time to time, the Company may participate in selected investment or strategic arrangements to expand its operations, customer base or geographic reach, including arrangements that combine the Company’s skills and resources with those of others to allow for the performance of particular projects. The Company holds undivided interests, ranging from 85% to 90%, in multiple proportionately consolidated non-controlled contractual joint ventures that provide infrastructure construction services for electrical transmission projects. The Company also holds a 35% undivided interest in a proportionately consolidated non-controlled Canadian contractual joint venture that was underway when the Company acquired Pacer in 2014, whose sole activity involves the construction of a bridge, a business in which the Company does not otherwise engage. This joint venture, which is managed by a third party, and for which the Company has minimal direct construction involvement, automatically terminates upon completion of the project. Income and/or losses incurred by these joint ventures are generally shared proportionally by the respective joint venture members, with the members of the joint ventures jointly and severally liable for all of the obligations of the joint venture. The respective joint venture agreements provide that each joint venture partner indemnify the other party for any liabilities incurred by such joint venture in excess of its ratable portion of such liabilities. Thus, it is possible that the Company could be required to pay or perform obligations in excess of its share if the other joint venture partners fail or refuse to pay or perform their respective share of the obligations. As of June 30, 2018, the Company was not aware of circumstances that would reasonably lead to material future claims against it in connection with these arrangements. Included in the Company’s cash balances as of June 30, 2018 and December 31, 2017 are amounts held by entities that are proportionately consolidated totaling $17.9 million and $17.3 million, respectively. These amounts are available to support the operations of those entities, but are not available for the Company’s other operations. Advances on project work associated with the Company’s proportionately consolidated contractual joint ventures, which are reflected within other current liabilities, totaled $10.3 million as of June 30, 2018. The Company has other investment arrangements, as discussed in Note 4 - Fair Value of Financial Instruments and Note 15 - Related Party Transactions. The Company may incur costs or provide financing, performance, financial and/or other guarantees to or in connection with these arrangements. Self-Insurance. MasTec maintains insurance policies for workers’ compensation, general liability and automobile liability, which are subject to per claim deductibles. The Company is self-insured up to the amount of the deductible. The Company also maintains excess umbrella coverage. As of June 30, 2018 and December 31, 2017, MasTec’s liability for unpaid claims and associated expenses, including incurred but not reported losses related to these policies, totaled $101.7 million and $106.2 million, respectively, of which $65.6 million and $72.2 million, respectively, were reflected within other long-term liabilities in the consolidated balance sheets. MasTec also maintains an insurance policy with respect to employee group medical claims, which is subject to annual per employee maximum losses. MasTec’s estimated liability for employee group medical claims totaled $2.5 million and $2.6 million as of June 30, 2018 and December 31, 2017, respectively. The Company is required to post collateral, generally in the form of letters of credit, and provide cash collateral to certain of its insurance carriers and to provide surety bonds in certain states. Insurance-related letters of credit for the Company’s workers’ compensation, general liability and automobile liability policies amounted to $87.8 million and $88.9 million as of June 30, 2018 and December 31, 2017, respectively. In addition, cash collateral deposited with insurance carriers, which is included within other long-term assets, amounted to $1.6 million for these policies as of both June 30, 2018 and December 31, 2017. Outstanding surety bonds related to workers’ compensation self-insurance programs amounted to $15.2 million as of both June 30, 2018 and December 31, 2017. Employment Agreements. The Company has employment agreements with certain executives and other employees, which provide for compensation and certain other benefits and for severance payments under certain circumstances. Certain employment agreements also contain clauses that become effective upon a change in control of the Company. Upon the occurrence of any of the defined events in the various employment agreements, the Company would be obligated to pay certain amounts to the relevant employees, which vary with the level of the employees’ respective responsibility. Collective Bargaining Agreements and Multiemployer Plans. As discussed in Note 10 - Other Retirement Plans, certain of MasTec’s subsidiaries are party to various collective bargaining agreements with unions representing certain of their employees, which require the Company to pay specified wages, provide certain benefits and contribute certain amounts to MEPPs. The Employee Retirement Income Security Act of 1974, as amended by the Multiemployer Pension Plan Amendments Act of 1980 (collectively, “ERISA”), which governs U.S.-registered multiemployer pension plans, subjects employers to substantial liabilities in the event of an employer’s complete or partial withdrawal from, or upon termination of, such plans. The Company currently contributes, and in the past, has contributed to, plans that are underfunded, and, therefore, could have potential liability associated with a voluntary or involuntary withdrawal from, or termination of, these plans. As of June 30, 2018, the Company does not have plans to withdraw from, and is not aware of circumstances that would reasonably lead to material claims against it, in connection with the MEPPs in which it participates. There can be no assurance, however, that the Company will not be assessed liabilities in the future, including in the form of a surcharge on future benefit contributions. The amount the Company could be obligated to pay or contribute in the future cannot be estimated, as these amounts are based on future levels of work of the union employees covered by these plans, investment returns and the level of underfunding of such plans. Indemnities. The Company generally indemnifies its customers for the services it provides under its contracts, as well as other specified liabilities, which may subject the Company to indemnity claims, liabilities and related litigation. As of June 30, 2018 and December 31, 2017, the Company was not aware of any material asserted or unasserted claims in connection with these indemnity obligations. Other Guarantees. In the ordinary course of its business, from time to time, MasTec guarantees the obligations of its subsidiaries, including obligations under certain contracts with customers, certain lease obligations and in some states, obligations in connection with obtaining contractors’ licenses. MasTec has also issued performance and other guarantees in connection with certain of its equity investments. MasTec also generally warrants the work it performs for a one to two year period following substantial completion of a project. Much of the work performed by the Company is evaluated for defects shortly after the work is completed. Accrued warranty claims are not, and have historically not been, material. However, if warranty claims occur, the Company could be required to repair or replace warrantied items, or, if customers elect to repair or replace the warrantied item using the services of another provider, the Company could be required to pay for the cost of the repair or replacement. Concentrations of Risk. The Company had approximately 395 customers for the six month period ended June 30, 2018. As of June 30, 2018, three customers each accounted for approximately 39%, 18% and 12%, respectively, of the Company’s consolidated net accounts receivable position, which represents accounts receivable, net, less BIEC, and, as of December 31, 2017, two customers each accounted for approximately 46% and 15%, respectively, of the Company’s consolidated net accounts receivable position. In addition, the Company derived 76% and 84%, respectively, of its revenue from its top ten customers for the three month periods ended June 30, 2018 and 2017, and derived 73% and 79% of its revenue, respectively, from its top ten customers for the six month periods ended June 30, 2018 and 2017.

Related Party Transactions	6 Months Ended
Related Party Transactions	Jun. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Note 15 – Related Party Transactions MasTec purchases, rents and leases equipment and purchases various types of supplies and services used in its business from a number of different vendors on a non-exclusive basis, including entities that are associated with members of subsidiary management. For the three month periods ended June 30, 2018 and 2017, related party lease payments for operational facilities and equipment totaled approximately $10.8 million and $14.4 million, respectively, and for the six month periods ended June 30, 2018 and 2017, totaled approximately $18.3 million and $27.1 million, respectively. Payables associated with these related party lease payments totaled approximately $3.0 million and $0.1 million as of June 30, 2018 and December 31, 2017, respectively. Additionally, payments to related parties for various types of supplies and services, including ancillary construction services, project-related site restoration and marketing and business development activities, totaled approximately $4.4 million and $7.9 million for the three month periods ended June 30, 2018 and 2017, respectively, and totaled $13.3 million and $14.5 million for the six month periods ended June 30, 2018 and 2017, respectively. As of June 30, 2018 and December 31, 2017, related amounts payable totaled approximately $14.2 million and $5.2 million, respectively. MasTec performs certain construction services for two entities, of which a member of subsidiary management is a minority owner. Revenue from these arrangements totaled approximately $3.6 million and $6.3 million for the three and six month periods ended June 30, 2018, respectively, and related amounts receivable, net of BIEC, totaled approximately $0.3 million and $0.2 million as of June 30, 2018 and December 31, 2017, respectively. In 2017, MasTec acquired an oil and gas pipeline equipment company that was formerly owned by a member of subsidiary management for approximately $40.6 million in cash and an estimated earn-out liability of $59.9 million, as adjusted, of which $5.7 million was paid in the second quarter of 2018. MasTec previously leased equipment from this company. In February 2018, MasTec acquired a construction management firm specializing in steel building systems, of which Juan Carlos Mas, who is the brother of Jorge Mas, Chairman of MasTec’s Board of Directors, and José R. Mas, MasTec’s Chief Executive Officer, was a minority owner, for approximately $6.1 million in cash and an estimated earn-out liability of approximately $0.7 million, as adjusted. The net assets acquired included notes payable to the former owners totaling approximately $2.6 million, which amount was subsequently repaid. MasTec rents and leases equipment and purchases equipment supplies used in its business from CCI, in which it has a 15% equity investment. Juan Carlos Mas serves as the chairman of CCI, and a member of management of a MasTec subsidiary is a minority owner. For the three month periods ended June 30, 2018 and 2017, MasTec paid CCI approximately $5.0 million and $11.0 million, net of rebates, respectively, for equipment supplies, rentals, leases and servicing, and for the six month periods ended June 30, 2018 and 2017, MasTec paid CCI approximately $10.9 million and $12.0 million, net of rebates, respectively. Amounts payable to CCI, net of rebates receivable, totaled approximately $14.4 million as of June 30, 2018, and as of December 31, 2017, were de minimis. MasTec has a subcontracting arrangement with an entity for the performance of construction services, the minority owners of which include an entity controlled by Jorge Mas and José R. Mas, along with two members of management of a MasTec subsidiary. For the three month periods ended June 30, 2018 and 2017, MasTec incurred approximately $1.8 million and $15.0 million, respectively, of expenses under this subcontracting arrangement, and for the six month periods ended June 30, 2018 and 2017, MasTec incurred approximately $6.8 million and $15.5 million, respectively. As of June 30, 2018 and December 31, 2017, related amounts payable totaled approximately $2.3 million and $2.0 million, respectively. MasTec leases employees to a customer in which Jorge Mas and José R. Mas own a majority interest. For both the three month periods ended June 30, 2018 and 2017, MasTec charged approximately $0.2 million to this customer, and for both the six month periods ended June 30, 2018 and 2017, charged $0.4 million. As of both June 30, 2018 and December 31, 2017, outstanding receivables related to this employee leasing arrangement totaled approximately $0.2 million. The Company also provides satellite communication services to this customer. For both the three month periods ended June 30, 2018 and 2017, revenue from satellite communication services provided to this customer totaled approximately $0.2 million, and for the six month periods ended June 30, 2018 and 2017, totaled approximately $0.5 million and $0.4 million, respectively. As of both June 30, 2018 and December 31, 2017, amounts receivable from this arrangement totaled approximately $0.3 million. MasTec has a leasing arrangement for an aircraft that is owned by an entity that Jorge Mas owns. For both the three month periods ended June 30, 2018 and 2017, MasTec paid approximately $0.5 million under this leasing arrangement, and for the six month periods ended June 30, 2018 and 2017, paid approximately $1.1 million and $1.0 million, respectively. As of both June 30, 2018 and December 31, 2017, related amounts payable were de minimis. The Company has a 40% interest in an entity related to a 2017 acquisition that is accounted for as an equity method investment. As of June 30, 2018 and December 31, 2017, advances outstanding from this entity, net, totaled approximately $0.1 million and $0.3 million, respectively. The Company’s Pacer subsidiary has a subcontracting arrangement with a contractual joint venture in which it holds a 35% undivided interest. For both the three month periods ended June 30, 2018 and 2017, revenue recognized by the Company in connection with this arrangement totaled approximately $0.2 million, and for the six month periods ended June 30, 2018 and 2017, totaled approximately $0.4 million and $0.3 million, respectively. As of June 30, 2018 and December 31, 2017, accounts receivable, net of BIEC, from this contractual joint venture totaled approximately $0.1 million and $0.8 million, respectively. Outstanding performance guarantees on behalf of this contractual joint venture, which are based on the original full contract value of the associated project, totaled Canadian $132.1 million as of both June 30, 2018 and December 31, 2017 (or approximately $100.5 million and $105.1 million, respectively). Additionally, the Company provided project-related financing in connection with this contractual joint venture of approximately $1.5 million and $2.3 million for the three month periods ended June 30, 2018 and 2017, respectively, and approximately $2.1 million and $3.1 million for the six month periods ended June 30, 2018 and 2017, respectively. Non-controlling interests in entities consolidated by the Company represent ownership interests held by members of management of certain of the Company’s subsidiaries, primarily in the Company’s Oil and Gas segment. The Company made distributions of earnings to holders of its non-controlling interests of $0.6 million in the first quarter of 2018 and $1.3 million in the first quarter of 2017. In October 2017, the Company acquired the remaining non-controlling interests of one of these entities, with which it had a subcontracting arrangement for the performance of ancillary oil and gas construction services, for approximately $21.4 million in cash and an estimated earn-out liability of $10.0 million, as adjusted, of which $4.6 million was paid in the second quarter of 2018. Split Dollar Agreements In the first quarter of 2018, Jorge Mas, the Company, and José R. Mas and Juan Carlos Mas, as trustees of the Jorge Mas trust, entered into an amended and restated split dollar life insurance agreement that replaced the prior split dollar agreement with Jorge Mas. Additionally, in the first quarter of 2018, José R. Mas, the Company, and Jorge Mas, Juan Carlos Mas and Patricia Mas, as trustees of the José R. Mas trust, entered into an amended and restated split dollar life insurance agreement that replaced the prior split dollar life insurance agreement with José R. Mas. For details of the amended and restated split dollar life insurance agreements with each of Jorge and José R. Mas, see Note 15 - Related Party Transactions in the Company’s 2017 Form 10-K. The Company paid $0.5 million and $0.7 million in the second quarter of 2018 in connection with the current agreements for Jorge Mas and José R. Mas, respectively, and paid $0.5 million and $0.7 million in the second quarter of 2017 in connection with the predecessor agreements for Jorge Mas and José R. Mas, respectively. As of June 30, 2018 and December 31, 2017, life insurance assets associated with these agreements, which amounts are included within other long-term assets, totaled approximately $17.9 million and $16.6 million, respectively.

Supplemental Guarantor Financial Information

6 Months Ended

Jun. 30, 2018

Condensed Unaudited Financial Statements, Supplemental Guarantor Information [Abstract]

Supplemental Guarantor Financial Information

Note 16 – Supplemental Guarantor Condensed Unaudited Consolidating Financial Information

The 4.875% Senior Notes are fully and unconditionally guaranteed on an unsecured, unsubordinated, joint and several basis by certain of the Company’s existing and future 100%-owned direct and indirect domestic subsidiaries that are, as of June 30, 2018, each guarantors of the Credit Facility or other outstanding indebtedness (the “Guarantor Subsidiaries”). The Company’s subsidiaries organized outside of the United States and certain domestic subsidiaries (collectively, the “Non-Guarantor Subsidiaries”) do not guarantee these notes. A Guarantor Subsidiary’s guarantee is subject to release in certain customary circumstances, including upon the sale of a majority of the capital stock or substantially all of the assets of such Guarantor Subsidiary; if the Guarantor Subsidiary’s guarantee under the Company’s Credit Facility and other indebtedness is released or discharged (other than due to payment under such guarantee); or when the requirements for legal defeasance are satisfied or the obligations are discharged in accordance with the related indentures.

The following supplemental financial information sets forth the condensed unaudited consolidating balance sheets and the condensed unaudited consolidating statements of operations and comprehensive income (loss) and cash flows for MasTec, Inc., the Guarantor Subsidiaries on a combined basis, the Non-Guarantor Subsidiaries on a combined basis and the eliminations necessary to arrive at the information for the Company as reported on a consolidated basis. Eliminations represent adjustments to eliminate investments in subsidiaries and intercompany balances and transactions between or among MasTec, Inc., the Guarantor Subsidiaries and the Non-Guarantor Subsidiaries. Investments in subsidiaries are accounted for using the equity method for this presentation.

CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (in millions)



For the Three Months Ended June 30, 2018	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated MasTec, Inc.
Revenue	$	—		$	1,556.9		$	84.0		$	(23.1	)	$	1,617.8
Costs of revenue, excluding depreciation and amortization	—			1,309.1			80.6			(23.1		)	1,366.6
Depreciation and amortization	—			46.2			5.5			—			51.7
General and administrative expenses	0.8			63.1			3.7			—			67.6
Interest expense (income), net	—			37.1			(16.3		)	—			20.8
Equity in earnings of unconsolidated affiliates	—			—			(5.8		)	—			(5.8		)
Other expense (income), net	—			1.2			(0.4		)	—			0.8
(Loss) income before income taxes	$	(0.8	)	$	100.2		$	16.7		$	—		$	116.2
Benefit from (provision for) income taxes	0.2			(25.9		)	(10.1		)	—			(35.8		)
Net (loss) income before equity in income from subsidiaries	$	(0.6	)	$	74.3		$	6.6		$	—		$	80.4
Equity in income from subsidiaries, net of tax	81.1			—			—			(81.1		)	—
Net income (loss)	$	80.5		$	74.3		$	6.6		$	(81.1	)	$	80.4
Net loss attributable to non-controlling interests	—			—			(0.1		)	—			(0.1		)
Net income (loss) attributable to MasTec, Inc.	$	80.5		$	74.3		$	6.7		$	(81.1	)	$	80.5
Comprehensive income (loss)	$	81.8		$	74.3		$	8.0		$	(82.4	)	$	81.7



For the Three Months Ended June 30, 2017	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated MasTec, Inc.
Revenue	$	—		$	1,820.0		$	85.5		$	(15.3	)	$	1,890.2
Costs of revenue, excluding depreciation and amortization	—			1,557.9			83.7			(15.3		)	1,626.3
Depreciation and amortization	—			38.2			7.2			—			45.4
General and administrative expenses	0.6			66.7			3.5			—			70.8
Interest expense (income), net	—			30.5			(15.7		)	—			14.8
Equity in earnings of unconsolidated affiliates	—			—			(6.1		)	—			(6.1		)
Other (income) expense, net	—			(5.3		)	5.5			—			0.1
(Loss) income before income taxes	$	(0.6	)	$	132.0		$	7.4		$	—		$	138.8
Benefit from (provision for) income taxes	0.2			(47.9		)	(7.7		)	—			(55.4		)
Net (loss) income before equity in income from subsidiaries	$	(0.4	)	$	84.1		$	(0.3	)	$	—		$	83.3
Equity in income from subsidiaries, net of tax	82.1			—			—			(82.1		)	—
Net income (loss)	$	81.7		$	84.1		$	(0.3	)	$	(82.1	)	$	83.3
Net income (loss) attributable to non-controlling interests	—			1.8			(0.1		)	—			1.7
Net income (loss) attributable to MasTec, Inc.	$	81.7		$	82.3		$	(0.2	)	$	(82.1	)	$	81.7
Comprehensive income (loss)	$	79.5		$	84.1		$	(2.5	)	$	(79.9	)	$	81.2



For the Six Months Ended June 30, 2018	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated MasTec, Inc.
Revenue	$	—		$	2,822.5		$	269.6		$	(77.5	)	$	3,014.6
Costs of revenue, excluding depreciation and amortization	—			2,445.3			236.1			(77.5		)	2,603.9
Depreciation and amortization	—			89.5			12.1			—			101.6
General and administrative expenses	1.5			122.4			7.3			—			131.2
Interest expense (income), net	—			70.0			(32.1		)	—			37.9
Equity in earnings of unconsolidated affiliates	—			—			(11.4		)	—			(11.4		)
Other income, net	—			(1.4		)	(0.9		)	—			(2.3		)
(Loss) income before income taxes	$	(1.5	)	$	96.7		$	58.5		$	—		$	153.8
Benefit from (provision for) income taxes	0.4			(24.9		)	(22.3		)	—			(46.9		)
Net (loss) income before equity in income from subsidiaries	$	(1.1	)	$	71.8		$	36.2		$	—		$	106.9
Equity in income from subsidiaries, net of tax	108.2			—			—			(108.2		)	—
Net income (loss)	$	107.1		$	71.8		$	36.2		$	(108.2	)	$	106.9
Net loss attributable to non-controlling interests	—			—			(0.2		)	—			(0.2		)
Net income (loss) attributable to MasTec, Inc.	$	107.1		$	71.8		$	36.4		$	(108.2	)	$	107.1
Comprehensive income (loss)	$	115.5		$	71.8		$	44.7		$	(116.7	)	$	115.3



For the Six Months Ended June 30, 2017	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated MasTec, Inc.
Revenue	$	—		$	2,903.2		$	173.4		$	(28.2	)	$	3,048.4
Costs of revenue, excluding depreciation and amortization	—			2,446.5			179.2			(28.2		)	2,597.5
Depreciation and amortization	—			73.5			14.8			—			88.3
General and administrative expenses	1.2			126.4			8.0			—			135.6
Interest expense (income), net	—			58.4			(31.0		)	—			27.4
Equity in earnings of unconsolidated affiliates	—			—			(7.7		)	—			(7.7		)
Other (income) expense, net	—			(5.3		)	5.9			—			0.6
(Loss) income before income taxes	$	(1.2	)	$	203.7		$	4.2		$	—		$	206.8
Benefit from (provision for) income taxes	0.4			(74.2		)	(9.0		)	—			(82.8		)
Net (loss) income before equity in income from subsidiaries	$	(0.8	)	$	129.5		$	(4.8	)	$	—		$	124.0
Equity in income from subsidiaries, net of tax	123.4			—			—			(123.4		)	—
Net income (loss)	$	122.6		$	129.5		$	(4.8	)	$	(123.4	)	$	124.0
Net income (loss) attributable to non-controlling interests	—			1.6			(0.3		)	—			1.3
Net income (loss) attributable to MasTec, Inc.	$	122.6		$	127.9		$	(4.5	)	$	(123.4	)	$	122.6
Comprehensive income (loss)	$	122.3		$	129.5		$	(5.1	)	$	(123.1	)	$	123.6

CONDENSED UNAUDITED CONSOLIDATING BALANCE SHEETS (in millions)



As of June 30, 2018	MasTec, Inc.		Guarantor Subsidiaries		Non-Guarantor Subsidiaries		Eliminations			Consolidated MasTec, Inc.
Assets
Total current assets	$	—	$	2,125.9	$	270.4	$	(114.5	)	$	2,281.8
Property and equipment, net	—		687.7		51.7		—			739.4
Goodwill and other intangible assets, net	—		1,193.7		134.4		—			1,328.1
Investments in and advances to consolidated affiliates, net	1,411.8		928.1		831.7		(3,171.6		)	—
Other long-term assets	16.3		34.7		181.8		—			232.8
Total assets	$	1,428.1	$	4,970.1	$	1,470.0	$	(3,286.1	)	$	4,582.2
Liabilities and equity
Total current liabilities	$	—	$	1,200.6	$	166.7	$	(114.5	)	$	1,252.8
Long-term debt	—		1,522.9		10.1		—			1,533.0
Other long-term liabilities	—		352.9		13.1		—			366.0
Total liabilities	$	—	$	3,076.4	$	189.9	$	(114.5	)	$	3,151.8
Total equity	$	1,428.1	$	1,893.7	$	1,280.1	$	(3,171.6	)	$	1,430.4
Total liabilities and equity	$	1,428.1	$	4,970.1	$	1,470.0	$	(3,286.1	)	$	4,582.2



As of December 31, 2017	MasTec, Inc.		Guarantor Subsidiaries		Non-Guarantor Subsidiaries		Eliminations			Consolidated MasTec, Inc.
Assets
Total current assets	$	—	$	1,536.6	$	332.9	$	(17.1	)	$	1,852.4
Property and equipment, net	—		638.7		67.8		—			706.5
Goodwill and other intangible assets, net	—		1,187.9		141.0		—			1,328.9
Investments in and advances to consolidated affiliates, net	1,415.0		847.7		746.6		(3,009.3		)	—
Other long-term assets	15.8		23.4		139.6		—			178.8
Total assets	$	1,430.8	$	4,234.3	$	1,427.9	$	(3,026.4	)	$	4,066.6
Liabilities and equity
Total current liabilities	$	—	$	778.6	$	202.3	$	(17.1	)	$	963.8
Long-term debt	—		1,269.4		11.3		—			1,280.7
Other long-term liabilities	—		379.9		8.8		—			388.7
Total liabilities	$	—	$	2,427.9	$	222.4	$	(17.1	)	$	2,633.2
Total equity	$	1,430.8	$	1,806.4	$	1,205.5	$	(3,009.3	)	$	1,433.4
Total liabilities and equity	$	1,430.8	$	4,234.3	$	1,427.9	$	(3,026.4	)	$	4,066.6

CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF CASH FLOWS (in millions)



For the Six Months Ended June 30, 2018	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations		Consolidated MasTec, Inc.
Net cash (used in) provided by operating activities	$	—		$	(129.6	)	$	152.8		$	—	$	23.2
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired	—			(6.7		)	—			—		(6.7		)
Capital expenditures	—			(85.1		)	(2.9		)	—		(88.0		)
Proceeds from sale of property and equipment	—			12.3			1.6			—		13.9
Payments for other investments	—			(11.2		)	(24.5		)	—		(35.7		)
Proceeds from other investments	—			—			5.4			—		5.4
Net cash used in investing activities	$	—		$	(90.7	)	$	(20.4	)	$	—	$	(111.1	)
Cash flows from financing activities:
Proceeds from credit facilities	—			1,623.3			15.6			—		1,638.9
Repayments of credit facilities	—			(1,357.6		)	(17.0		)	—		(1,374.6		)
Repayments of other borrowings and capital lease obligations	—			(49.9		)	(3.8		)	—		(53.7		)
Payments of acquisition-related contingent consideration	—			(15.9		)	—			—		(15.9		)
Repurchase of common stock	(128.3		)	—			—			—		(128.3		)
Distributions to non-controlling interests	—			(0.6		)	—			—		(0.6		)
Proceeds from stock-based awards, net	1.9			—			—			—		1.9
Net financing activities and advances from (to) consolidated affiliates	126.4			11.8			(138.2		)	—		—
Net cash provided by (used in) financing activities	$	—		$	211.1		$	(143.4	)	$	—	$	67.7
Effect of currency translation on cash	—			—			0.5			—		0.5
Net decrease in cash and cash equivalents	$	—		$	(9.2	)	$	(10.5	)	$	—	$	(19.6	)
Cash and cash equivalents - beginning of period	$	—		$	10.0		$	30.3		$	—	$	40.3
Cash and cash equivalents - end of period	$	—		$	0.8		$	19.8		$	—	$	20.7



For the Six Months Ended June 30, 2017	MasTec, Inc.		Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations		Consolidated MasTec, Inc.
Net cash used in operating activities	$	—	$	(49.9	)	$	(50.3	)	$	—	$	(100.2	)
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired	—		(37.4		)	—			—		(37.4		)
Capital expenditures	—		(55.0		)	(1.9		)	—		(56.9		)
Proceeds from sale of property and equipment	—		6.8			0.6			—		7.4
Payments for other investments	—		(1.2		)	(73.3		)	—		(74.5		)
Proceeds from other investments	—		—			12.1			—		12.1
Net cash used in investing activities	$	—	$	(86.8	)	$	(62.5	)	$	—	$	(149.3	)
Cash flows from financing activities:
Proceeds from credit facilities	—		1,141.2			12.0			—		1,153.2
Repayments of credit facilities	—		(850.2		)	(18.9		)	—		(869.1		)
Repayments of other borrowings and capital lease obligations	—		(36.4		)	(4.7		)	—		(41.1		)
Payments of acquisition-related contingent consideration	—		(6.7		)	—			—		(6.7		)
Distributions to non-controlling interests	—		(1.3		)	—			—		(1.3		)
Proceeds from stock-based awards, net	0.0		—			—			—		0.0
Other financing activities	—		(6.2		)	—			—		(6.2		)
Net financing activities and advances (to) from consolidated affiliates	—		(120.6		)	120.6			—		—
Net cash provided by financing activities	$	—	$	119.8		$	109.0		$	—	$	228.8
Effect of currency translation on cash	—		—			0.1			—		0.1
Net decrease in cash and cash equivalents	$	—	$	(16.9	)	$	(3.7	)	$	—	$	(20.5	)
Cash and cash equivalents - beginning of period	$	—	$	28.9		$	9.9		$	—	$	38.8
Cash and cash equivalents - end of period	$	—	$	12.0		$	6.2		$	—	$	18.2

Business, Basis of Presentation and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions for Form 10-Q and Rule 10-01 of Regulation S-X. Pursuant to these rules and regulations, certain information and footnote disclosures normally included in the annual audited consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The accompanying condensed consolidated balance sheet as of December 31, 2017 is derived from the Company’s audited financial statements as of that date. Because certain information and footnote disclosures have been condensed or omitted, these condensed unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto as of and for the year ended December 31, 2017 contained in the Company’s 2017 Annual Report on Form 10-K (the “2017 Form 10-K”). In management’s opinion, all normal and recurring adjustments considered necessary for a fair presentation of the financial position, results of operations and cash flows for the periods presented have been included. Certain prior year amounts have been reclassified to conform to the current period presentation. Interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. The Company believes that the disclosures made in these condensed unaudited consolidated financial statements are adequate to make the information not misleading.
Reclassifications	Certain prior year amounts have been reclassified to conform to the current period presentation.
Principles of Consolidation	Principles of Consolidation The accompanying condensed unaudited consolidated financial statements include MasTec, Inc. and its subsidiaries and include the accounts of all majority owned subsidiaries over which the Company exercises control and, when applicable, entities in which the Company has a controlling financial interest. All significant intercompany balances and transactions have been eliminated in consolidation. Other parties’ interests in entities that MasTec consolidates are reported as non-controlling interests within equity. Net income or loss attributable to non-controlling interests is reported as a separate line item below net income or loss. The Company’s investments in entities for which the Company does not have a controlling interest, but for which it has the ability to exert significant influence, are accounted for using the equity method of accounting. Equity method investments are recorded as other long-term assets. Income or loss from these investments is recorded as a separate line item in the statements of operations. Intercompany profits or losses associated with the Company’s equity method investments are eliminated until realized by the investee in transactions with third parties. For equity investees in which the Company has an undivided interest in the assets, liabilities and profits or losses of an unincorporated entity, but the Company does not exercise control over the entity, the Company consolidates its proportional interest in the accounts of the entity. Equity investments, other than those accounted for as equity method investments or those that are consolidated, are measured at fair value if their fair values are readily determinable. Equity investments that do not have readily determinable fair values are measured at cost, adjusted for changes from observable market transactions, less impairment. Realized and unrealized gains or losses related to equity investments are recognized in other income or expense. Management determines whether each business entity in which it has equity interests, debt, or other investments constitutes a variable interest entity (“VIE”) based on the nature and characteristics of such arrangements. If an investment arrangement is determined to be a VIE, then management determines if the Company is the VIE’s primary beneficiary by evaluating several factors, including the Company’s: (i) risks and responsibilities; (ii) ownership interests; (iii) decision making powers; and (iv) financial interests, among other factors. If management determines the Company is the primary beneficiary of a VIE, then it would be consolidated, and other parties’ interests in the VIE would be accounted for as non-controlling interests. The primary beneficiary consolidating the VIE must normally have both (i) the power to direct the primary activities of the VIE and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE, which, in either case, could be significant to the VIE. As of June 30, 2018, the Company determined that certain of its investment arrangements were VIEs. The Company does not, however, have the power to direct the primary activities that most significantly impact the economic performance of these VIEs and the Company is not the primary beneficiary; accordingly, it has not consolidated these VIEs.
Equity Method Investments	The Company’s investments in entities for which the Company does not have a controlling interest, but for which it has the ability to exert significant influence, are accounted for using the equity method of accounting. Equity method investments are recorded as other long-term assets. Income or loss from these investments is recorded as a separate line item in the statements of operations. Intercompany profits or losses associated with the Company’s equity method investments are eliminated until realized by the investee in transactions with third parties.
Unincorporated Entities, Proportionate Consolidation	For equity investees in which the Company has an undivided interest in the assets, liabilities and profits or losses of an unincorporated entity, but the Company does not exercise control over the entity, the Company consolidates its proportional interest in the accounts of the entity.
Other Equity Investments With Readily Determinable Fair Values	Equity investments, other than those accounted for as equity method investments or those that are consolidated, are measured at fair value if their fair values are readily determinable.
Other Equity Investments Without Readily Determinable Fair Values	Equity investments that do not have readily determinable fair values are measured at cost, adjusted for changes from observable market transactions, less impairment. Realized and unrealized gains or losses related to equity investments are recognized in other income or expense.
Variable Interest Entities	Management determines whether each business entity in which it has equity interests, debt, or other investments constitutes a variable interest entity (“VIE”) based on the nature and characteristics of such arrangements. If an investment arrangement is determined to be a VIE, then management determines if the Company is the VIE’s primary beneficiary by evaluating several factors, including the Company’s: (i) risks and responsibilities; (ii) ownership interests; (iii) decision making powers; and (iv) financial interests, among other factors. If management determines the Company is the primary beneficiary of a VIE, then it would be consolidated, and other parties’ interests in the VIE would be accounted for as non-controlling interests. The primary beneficiary consolidating the VIE must normally have both (i) the power to direct the primary activities of the VIE and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE, which, in either case, could be significant to the VIE. As of June 30, 2018, the Company determined that certain of its investment arrangements were VIEs. The Company does not, however, have the power to direct the primary activities that most significantly impact the economic performance of these VIEs and the Company is not the primary beneficiary; accordingly, it has not consolidated these VIEs.
Translation of Foreign Currencies	Translation of Foreign Currencies The assets and liabilities of foreign subsidiaries with a functional currency other than the U.S. dollar are translated into U.S. dollars at period-end exchange rates, with resulting translation gains or losses accumulated within other comprehensive income or loss. Revenue and expenses are translated into U.S. dollars at average rates of exchange during the applicable period. Substantially all of the Company’s foreign operations use their local currency as their functional currency. Currency gains or losses resulting from transactions executed in currencies other than the functional currency are included in other income or expense, net.
Management Estimates	Management Estimates The preparation of consolidated financial statements in accordance with U.S. GAAP requires the use of estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. These estimates are based on historical experience and various other assumptions, the results of which form the basis of making judgments about the Company’s operating results and the carrying values of assets and liabilities that are not readily apparent from other sources. Key estimates include: the recognition of revenue and project profit or loss, which the Company defines as project revenue, less project costs of revenue, including project-related depreciation, in particular, on construction contracts accounted for under the cost-to-cost method, for which the recorded amounts require estimates of costs to complete and the amount of variable consideration included in the contract transaction price; allowances for doubtful accounts; fair value estimates, including those related to business acquisitions, valuations of goodwill and intangible assets, acquisition-related contingent consideration and equity investments; asset lives used in computing depreciation and amortization; fair values of financial instruments; self-insurance liabilities; other accruals and allowances; income taxes; and the estimated effects of litigation and other contingencies. While management believes that such estimates are reasonable when considered in conjunction with the Company’s consolidated financial position and results of operations taken as a whole, actual results could differ materially from those estimates.
Revenue Recognition	Revenue Recognition The Company adopted the requirements of Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which is also referred to as Accounting Standards Codification (“ASC”) Topic 606 (“Topic 606”), under the modified retrospective transition approach effective January 1, 2018, with application to all existing contracts that were not substantially completed as of January 1, 2018. The difference between the recognition criteria under Topic 606 and the Company’s previous revenue recognition practices under the previous revenue recognition guidance, ASC Topic 605-35, was recognized through a cumulative effect adjustment of approximately $2 million that was made to the opening balance of retained earnings as of January 1, 2018. Consistent with the modified retrospective transition approach, the comparative 2017 prior period was not adjusted to conform to the current period presentation. Under Topic 606, revenue is recognized when, or as, control of promised goods and services is transferred to customers, and the amount of revenue recognized reflects the consideration to which an entity expects to be entitled in exchange for the goods and services transferred. The adoption of Topic 606 did not have, and is not expected to have, a material effect on the timing or amount of revenue recognized as compared with the Company’s previous revenue recognition practices. Revenue is recognized by the Company primarily over time utilizing the cost-to-cost measure of progress for fixed price contracts and certain master service and other service agreements, consistent with the Company’s previous revenue recognition practices. Under Topic 606, the cost-to-cost measure of progress best depicts the transfer of control of goods or services to the customer for these contracts. Contracts. The Company derives revenue primarily from construction projects performed: i) under master and other service agreements, which provide a menu of available services in a specific geographic territory that are utilized on an as-needed basis, and are typically priced using time and materials or a fixed price per unit basis; or ii) under contracts for specific projects requiring the construction and installation of an entire infrastructure system or specified units within an infrastructure system, which are subject to multiple pricing options, including fixed price, unit price, time and materials, or cost plus a markup. Revenue derived from master service and other service agreements totaled 37% and 31% of consolidated revenue for the three month periods ended June 30, 2018 and 2017, respectively, and totaled 38% and 37% for the six month periods ended June 30, 2018 and 2017, respectively. Fixed price contracts provide for a fixed amount of revenue for the entire project. Revenue from these contracts, as well as for certain projects pursuant to master and other service agreements, is recognized over time using the cost-to-cost measure of progress. For these contracts, the cost-to-cost measure of progress best depicts the continuous transfer of control of goods or services to the customer. Such contracts provide that the customer accept completion of progress to date and compensate the Company for services rendered. For certain of the Company’s master service and other service agreements, under which it performs installation and maintenance services, primarily for install-to-the-home service providers in its Communications segment, revenue is recognized at a point in time. This is generally when the work order has been fulfilled, which is typically the same day the work is initiated. Point in time revenue accounted for approximately 7% and 8% of consolidated revenue for the three and six month periods ended June 30, 2018, respectively. Substantially all of the Company’s other revenue is recognized over time. Contract costs include all direct materials, labor and subcontracted costs, as well as indirect costs related to contract performance, such as indirect labor, supplies, tools, repairs and the operational costs of capital equipment. The cost estimation process for recognizing revenue over time under the cost-to-cost method is based on the professional knowledge and experience of the Company’s project managers, engineers and financial professionals. Management reviews estimates of total contract transaction price and total project costs on an ongoing basis. Changes in job performance, job conditions and management’s assessment of expected variable consideration are factors that influence estimates of the total contract transaction price, total costs to complete those contracts and profit recognition. Changes in these factors could result in revisions to revenue in the period in which the revisions are determined, which could materially affect the Company’s consolidated results of operations for that period. Provisions for losses on uncompleted contracts are recorded in the period in which such losses are determined. For both the six month periods ended June 30, 2018 and 2017, project profit was affected by less than 5% as a result of changes in contract estimates included in projects that were in process as of December 31, 2017 and 2016. Revenue recognized for the three and six month periods ended June 30, 2018 from performance obligations satisfied, or work completed, in prior periods totaled approximately $5.2 million and $47.4 million, respectively, which represents the effect on revenue for the periods presented of changes in transaction prices from variable consideration on certain projects. The timing of customer billings is generally dependent upon advance billing terms, milestone billings based on the completion of certain phases of the work, or when services are provided. Under the typical payment terms of master and other service agreements and fixed price contracts, the customer makes progress payments based on quantifiable measures of performance by the Company as defined by each specific agreement. Progress payments, generally net of amounts retained, are paid by the customer over the duration of the contract. For install-to-the-home contracts, work orders are billed and paid as completed. Amounts billed and due from customers, as well as the amount of contract assets, are classified within accounts receivable, net, in the consolidated balance sheets. See Note 5 - Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities for related discussion. Amounts expected to be collected beyond one year are classified as other long-term assets. Performance Obligations. A performance obligation is a contractual promise to transfer a distinct good or service to a customer, and is the unit of account under Topic 606. The transaction price of a contract is allocated to each distinct performance obligation and recognized as revenue when or as the performance obligation is satisfied. The Company’s contracts often require significant integration services, and even when delivering multiple distinct services, are generally accounted for as a single performance obligation. Contract amendments and change orders are generally not distinct from the existing contract and are accounted for as a modification of the existing contract and performance obligation. The majority of the Company’s performance obligations are completed within one year. When more than one contract is entered into with a customer on or close to the same date, the Company evaluates whether those contracts should be combined and accounted for as a single contract as well as whether those contracts should be accounted for as one, or more than one, performance obligation. This evaluation requires significant judgment and is based on the facts and circumstances of the various contracts. Remaining performance obligations represent the amount of unearned transaction prices under contracts for which work is wholly or partially unperformed. As of June 30, 2018, the amount of the Company’s remaining performance obligations was $5.1 billion. The Company expects to recognize approximately $3.0 billion of its remaining performance obligations as revenue during the remainder of 2018, with the balance to be recognized primarily in 2019. Variable Consideration. Transaction prices for the Company’s contracts may include variable consideration, which comprises items such as change orders, claims, incentives and liquidated damages. Management estimates variable consideration for a performance obligation utilizing estimation methods that best predict the amount of consideration to which the Company will be entitled. Variable consideration is included in the estimated transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Management’s estimates of variable consideration and determination of whether to include estimated amounts in transaction price are based largely on engineering studies and legal opinions, past practices with the customer, specific discussions, correspondence or preliminary negotiations with the customer and all other relevant information that is reasonably available. The effect of variable consideration on the transaction price of a performance obligation is typically recognized as an adjustment to revenue on a cumulative catch-up basis. To the extent unapproved change orders, claims and liquidated damages reflected in transaction price are not resolved in the Company’s favor, or to the extent incentives reflected in transaction price are not earned, there could be reductions in, or reversals of, previously recognized revenue. As of June 30, 2018 and December 31, 2017, the Company included approximately $190 million and $146 million, respectively, of change orders and/or claims in the transaction price for certain contracts that were in the process of being resolved in the normal course of business, including through negotiation, arbitration and other proceedings. These transaction price adjustments are included within costs and earnings in excess of billings or accounts receivable, net of allowance, as appropriate. As of both June 30, 2018 and December 31, 2017, these change orders and/or claims were primarily related to certain large long-haul pipeline construction projects in the Oil and Gas segment that have either recently been completed, or are expected to reach substantial completion in the coming months. The Company actively engages with its customers to complete the final approval process, and generally expects these processes to be completed within one year. Amounts ultimately realized upon final acceptance by customers could be higher or lower than such estimated amounts.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements See the revenue recognition discussion within Significant Accounting Policies above, and the recent accounting pronouncements discussion below, for information pertaining to the effects of recently adopted and other recent accounting pronouncements, as updated from the discussion in the Company’s 2017 Form 10-K. Other Accounting Pronouncements Adopted in 2018 In August 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”) to reduce diversity in practice by providing guidance on the classification of certain cash receipts and payments in the statement of cash flows. This ASU, which the Company adopted as of January 1, 2018, is effective on a retrospective basis, and resulted in the reclassification of certain types of activity in the consolidated statement of cash flows, including the reclassification of $12 million of second quarter 2017 acquisition-related contingent consideration payments in excess of acquisition date liabilities from financing to operating cash flows. Additionally, in connection with the adoption of this ASU, the Company elected to account for distributions received from equity method investees using the nature of distributions approach, under which distributions are classified based on the nature of the activity that generated them. The other provisions of this ASU did not have a material effect on the Company’s consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which was further amended in February and in March 2018 by ASU 2018-03, Technical Corrections and Improvements to Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2018-03”) and ASU 2018-04, Investments - Debt Securities (Topic 320) and Regulated Operations (Topic 980):Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 117 and SEC Release No. 33-9273 (“ASU 2018-04”) to clarify certain aspects of ASU 2016-01 and to update Securities and Exchange Commission (“SEC”) interpretive guidance in connection with the provisions of ASU 2016-01. These ASUs provide guidance for the recognition, measurement, presentation and disclosure of financial assets and financial liabilities, including equity investments other than those accounted for under the equity method of accounting or those that are consolidated. Equity investments within the scope of these ASUs are required to be measured at fair value with changes in fair value recognized in net income. Equity investments that do not have readily determinable fair values are permitted to be measured at cost, less any impairment, plus or minus any changes resulting from observable price changes for identical or similar investments of the same issuer (the “measurement alternative”). The Company adopted these ASUs as of January 1, 2018, which was applicable to the Company on a prospective basis for its equity investments as they do not have readily determinable fair values, and for which the Company elected to utilize the measurement alternative. The adoption of these ASUs will result in volatility in other income (expense), net, upon the occurrence of any observable price changes or impairments related to its equity investments. For further information pertaining to the Company’s equity investments, see Note 4 - Fair Value of Financial Instruments. The other provisions of these ASUs did not have a material effect on the Company’s consolidated financial statements. Other Recent Accounting Pronouncements In June 2018, the FASB issued ASU 2018-07, Compensation-Stock Compensation (Topic 718) - Improvements to Nonemployee Share-Based Payment Accounting (“ASU 2018-07”). ASU 2018-07 expands the guidance in Topic 718 to include share-based payments for goods and services to non-employees and generally aligns it with the guidance for share-based payments to employees. ASU 2018-07 is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the effect of this ASU on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) (“ASU 2016-02”), which was further clarified and amended in July 2018 by ASU 2018-10, Codification Improvements to Topic 842, Leases (“ASU 2018-10”) and ASU 2018-11, Leases (Topic 842): Targeted Improvements (“ASU 2018-11”). These ASUs provide revised guidance for lease accounting and related disclosure requirements, including a requirement for lessees to recognize right-of use assets and lease liabilities on the balance sheet for leases with durations greater than twelve months. These ASUs are effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. As issued, ASU 2016-02 required modified retrospective application for all leases existing as of, or entered into after, the beginning of the earliest comparative period presented in the consolidated financial statements, with certain practical expedients available. ASU 2018-11 simplifies the transition requirements by providing companies an option to initially apply the new lease requirements as of the date of adoption and recognize a cumulative effect adjustment to the opening balance of retained earnings in the period of adoption. Under this guidance, comparative periods would not need to be restated. The Company will adopt these ASUs as of January 1, 2019, and upon adoption, expects to utilize the package of practical expedients that allow entities to retain the classification of lease contracts existing as of the date of adoption. The Company is evaluating the transition alternatives as provided under ASU 2018-11. The Company is continuing to assess the potential effects of these ASUs, which have not yet been quantified, on its consolidated financial statements, business processes, systems and controls. The Company’s assessment, which it expects to substantially complete in the fourth quarter of 2018, includes an evaluation of its existing lease portfolio, a comparison of its historical accounting policies and practices to the new standard, and an evaluation of the effect of certain accounting policy elections. The Company expects to implement a new lease accounting and administration software solution in connection with the new standard. In addition, the Company is evaluating certain changes to its current business processes and internal controls to meet the reporting and disclosure requirements of the new standard. These ASUs are not expected to have a material effect on the amount of expense recognized in connection with the Company’s current leasing arrangements as compared to current practice, however, based on the Company’s preliminary review of its lease contracts to date, it anticipates that it will recognize incremental lease assets and liabilities on its consolidated balance sheets upon adoption of the standard, and that the amount of such incremental lease assets and lease liabilities will be material. The Company’s expectations may change as its assessment progresses. For information about the Company’s future lease commitments as of December 31, 2017, see Note 8 - Lease Obligations, in the Company’s 2017 Form 10-K.

Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Schedule of Earnings Per Share Information

The following table provides details underlying the Company’s earnings per share calculations for the periods indicated (in thousands):



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2018		2017		2018		2017
Net income attributable to MasTec:
Net income - basic and diluted ^(a)	$	80,492	$	81,668	$	107,052	$	122,638
Weighted average shares outstanding:
Weighted average shares outstanding - basic	78,984		80,925		80,061		80,812
Dilutive common stock equivalents	1,078		1,367		1,075		1,414
Weighted average shares outstanding - diluted	80,062		82,292		81,136		82,226

Additional information:
Weighted average anti-dilutive common stock equivalents ^(b)	—		13		—		6


(a)	Calculated as total net income less amounts attributable to non-controlling interests.


(b)	Represents anti-dilutive common stock equivalents as calculated under the treasury stock method.

Goodwill and Other Intangible Assets (Tables)

6 Months Ended

Jun. 30, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill by Segment

The following table provides balances for goodwill by reportable segment as of June 30, 2018 (in millions):



	Communications		Oil and Gas			Electrical Transmission		Power Generation and Industrial		Total Goodwill
Goodwill, gross	$	467.8	$	458.1		$	149.9	$	142.4	$	1,218.2
Accumulated impairment loss	—		(71.6		)	—		—		(71.6		)
Goodwill, net	$	467.8	$	386.5		$	149.9	$	142.4	$	1,146.6

Rollforward of Other Intangible Assets

The following table provides a reconciliation of changes in other intangible assets, net, for the period indicated (in millions):



	Other Intangible Assets
	Non-Amortizing					Amortizing
	Trade Names		Pre-Qualifications			Customer Relationships and Backlog			Other ^(a)			Total
Other intangible assets, gross, as of December 31, 2017	$	34.5	$	77.6		$	223.0		$	21.8		$	356.9
Accumulated amortization						(152.4		)	(13.4		)	(165.8		)
Other intangible assets, net, as of December 31, 2017	$	34.5	$	77.6		$	70.6		$	8.4		$	191.1
Additions from new business combinations	—		—			2.9			0.3			3.2
Measurement period adjustments ^(b)	—		—			0.4			(0.7		)	(0.3		)
Amortization expense						(9.5		)	(0.8		)	(10.3		)
Currency translation adjustments	—		(2.0		)	(0.2		)	—			(2.2		)
Other intangible assets, net, as of June 30, 2018	$	34.5	$	75.6		$	64.2		$	7.2		$	181.5


(a)	Consists principally of trade names and non-compete agreements.


(b)	Represents adjustments to preliminary estimates of the fair values of intangible assets acquired within the measurement period for the Company’s 2017 acquisitions.

Schedule of Consideration Paid and Net Assets Acquired, Business Combinations

The following table summarizes the estimated fair values of consideration paid and net assets acquired as of the respective dates of acquisition, as adjusted (in millions):



Acquisition consideration:	2017
Cash	$	120.4
Fair value of contingent consideration (earn-out liability)	96.3
Total consideration transferred	$	216.7
Identifiable assets acquired and liabilities assumed:
Current assets, primarily composed of accounts receivable and $2.8 million of cash acquired	$	43.8
Property and equipment and other long-term assets	57.2
Amortizing intangible assets	28.1
Current liabilities, including current portion of capital lease obligations and long-term debt	(29.5		)
Long-term debt, including capital lease obligations	(9.9		)
Deferred income taxes and other long-term liabilities	(12.0		)
Total identifiable net assets	$	77.7
Goodwill	$	139.0
Total net assets acquired, including goodwill	$	216.7

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities (Tables)

6 Months Ended

Jun. 30, 2018

Receivables [Abstract]

Schedule of Accounts Receivable, Net of Allowance, and Contract Assets

The following table provides details of accounts receivable, net of allowance and contract assets (together, “accounts receivable, net”) as of the dates indicated (in millions):



	June 30, 2018			December 31, 2017
Contract billings	$	561.6		$	683.9
Less allowance for doubtful accounts	(9.5		)	(8.2		)
Accounts receivable, net of allowance	$	552.1		$	675.7
Retainage	317.9			323.1
Costs and earnings in excess of billings	1,207.5			599.2
Retainage and costs and earnings in excess of billings (together, “contract assets”)	$	1,525.4		$	922.3
Accounts receivable, net	$	2,077.5		$	1,598.0

Property and Equipment, Net (Tables)

6 Months Ended

Jun. 30, 2018

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment, Net

The following table provides details of property and equipment, net, including property and equipment held under capital leases as of the dates indicated (in millions):



	June 30, 2018			December 31, 2017
Land	$	4.6		$	4.6
Buildings and leasehold improvements	28.4			26.7
Machinery and equipment	1,319.5			1,261.9
Office furniture and equipment	157.3			149.9
Construction in progress	26.2			12.5
Total property and equipment	$	1,536.0		$	1,455.6
Less accumulated depreciation and amortization	(796.6		)	(749.1		)
Property and equipment, net	$	739.4		$	706.5

Debt (Tables)

6 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Schedule of Carrying Values of Debt

The following table provides details of the carrying values of debt as of the dates indicated (in millions):



Description	Maturity Date	June 30, 2018			December 31, 2017
Senior secured credit facility:	February 22, 2022
Revolving loans		$	648.1		$	377.7
Term loan		386.9			396.9
4.875% Senior Notes	March 15, 2023	400.0			400.0
Capital lease obligations, weighted average interest rate of 3.8%	In installments through May 1, 2023	182.6			181.2
Other debt obligations	Varies	11.1			25.8
Total long-term debt obligations		$	1,628.7		$	1,381.6
Less unamortized deferred financing costs		(11.5		)	(13.0		)
Total debt, net of deferred financing costs		$	1,617.2		$	1,368.6
Current portion of long-term debt		84.2			87.9
Long-term debt		$	1,533.0		$	1,280.7

Schedule of Activity, Restricted Shares

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Stock-Based Compensation and Other Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2018

Share-based Compensation [Abstract]



Activity, restricted shares: ^(a)	Restricted Shares		Per Share Weighted Average Grant Date Fair Value
Non-vested restricted shares, as of December 31, 2017	1,448,591		$	23.29
Granted	116,822		50.67
Vested	(36,477	)	21.85
Canceled/forfeited	(29,054	)	20.65
Non-vested restricted shares, as of June 30, 2018	1,499,882		$	25.51


(a)	Includes 19,300 and 27,550 restricted stock units as of June 30, 2018 and December 31, 2017, respectively.

Schedule of Employee Stock Purchase Plans

The following table provides details pertaining to the Company’s ESPPs for the periods indicated:



	For the Six Months Ended June 30,
	2018		2017
Cash proceeds (in millions)	$	2.2	$	1.6
Common shares issued	55,138		49,502
Weighted average price per share	$	39.99	$	33.30
Weighted average per share grant date fair value	$	9.74	$	8.67

Schedule of Non-Cash Stock-Based Compensation Expense and Related Tax Effects

Details of non-cash stock-based compensation expense and related tax effects for the periods indicated were as follows (in millions):



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2018		2017		2018		2017
Non-cash stock-based compensation expense	$	3.4	$	3.4	$	6.6	$	7.2
Income Tax Effects:
Income tax effect of non-cash stock-based compensation	$	1.0	$	1.3	$	1.8	$	2.5
Excess tax benefit from non-cash stock-based compensation ^(a)	$	0.2	$	0.0	$	0.2	$	0.1

(a)

Other Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2018

Multiemployer Plans [Abstract]

Schedule of Covered Employees and Contributions, Multiemployer Plans

Total contributions to multiemployer plans and the related number of employees covered by these plans, including with respect to the Company’s Canadian operations, for the periods indicated were as follows:



	Multiemployer Plans
	Covered Employees		Contributions (in millions)
	Low	High	Pension		Other Multiemployer		Total
For the Three Months Ended June 30:
2018	2,612	6,183	$	19.7	$	2.1	$	21.8
2017	3,669	7,057	$	28.3	$	2.7	$	31.0
For the Six Months Ended June 30:
2018	2,018	6,183	$	31.0	$	4.1	$	35.1
2017	550	7,057	$	32.0	$	5.3	$	37.3

Segments and Related Information (Tables)

6 Months Ended

Jun. 30, 2018

Segment Reporting [Abstract]

Schedule of Financial Information by Reportable Segment



	For the Three Months Ended June 30,						For the Six Months Ended June 30,
Revenue:	2018			2017			2018			2017
Communications ^(a)	$	618.6		$	592.2		$	1,245.7		$	1,151.7
Oil and Gas	769.3			1,140.4			1,305.8			1,596.2
Electrical Transmission	84.5			96.6			198.5			195.4
Power Generation and Industrial	146.0			60.7			263.6			107.3
Other	0.2			1.9			2.2			3.6
Eliminations	(0.8		)	(1.6		)	(1.2		)	(5.8		)
Consolidated revenue	$	1,617.8		$	1,890.2		$	3,014.6		$	3,048.4


(a)	Revenue generated primarily by utilities customers represented 13.6% and 11.5% of Communications segment revenue for the three month periods ended June 30, 2018 and 2017, respectively, and represented 15.7% and 12.4% for the six month periods ended June 30, 2018 and 2017, respectively.



	For the Three Months Ended June 30,						For the Six Months Ended June 30,
EBITDA:	2018			2017			2018			2017
Communications	$	73.7		$	59.5		$	155.8		$	107.8
Oil and Gas	122.7			154.0			155.7			247.9
Electrical Transmission	(2.7		)	3.5			1.9			6.7
Power Generation and Industrial	9.8			4.7			14.6			5.6
Other	6.8			6.8			12.7			1.5
Corporate	(21.6		)	(29.6		)	(47.5		)	(47.1		)
Consolidated EBITDA	$	188.7		$	198.9		$	293.2		$	322.4



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
Depreciation and Amortization:	2018		2017		2018		2017
Communications	$	15.3	$	13.5	$	29.9	$	25.5
Oil and Gas	26.1		23.2		51.6		45.1
Electrical Transmission	5.1		5.7		10.4		11.4
Power Generation and Industrial	3.6		1.4		6.6		2.9
Other	0.0		0.0		0.1		0.1
Corporate	1.6		1.6		3.0		3.3
Consolidated depreciation and amortization	$	51.7	$	45.4	$	101.6	$	88.3

Reconciliation of Consolidated Income before Income Taxes to EBITDA



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
EBITDA Reconciliation:	2018		2017		2018		2017
Income before income taxes	$	116.2	$	138.8	$	153.8	$	206.8
Plus:
Interest expense, net	20.8		14.8		37.9		27.4
Depreciation and amortization	51.7		45.4		101.6		88.3
Consolidated EBITDA	$	188.7	$	198.9	$	293.2	$	322.4

Schedule of Significant Customers, Revenue Concentration Information

Revenue concentration information for significant customers as a percentage of total consolidated revenue was as follows:



	For the Three Months Ended June 30,		For the Six Months Ended June 30,
Customer:	2018	2017	2018	2017
AT&T (including DIRECTV^®) ^(a)	25%	22%	26%	27%
Energy Transfer affiliates ^(b)	15%	47%	20%	35%
EQT Corporation ^(c)	19%	—%	11%	—%

(a)


(b)	The Company's relationship with Energy Transfer affiliates is based upon various construction contracts for pipeline activities with Energy Transfer Partners L.P., and its subsidiaries and affiliates, all of which are consolidated by Energy Transfer Equity, L.P. Revenue from Energy Transfer affiliates is included in the Oil and Gas segment.


(c)	The Company's relationship with EQT Corporation and its affiliates is based upon various construction contracts for pipeline activities. Revenue from EQT Corporation is included in the Oil and Gas segment.

Supplemental Guarantor Financial Information (Tables)

6 Months Ended

Jun. 30, 2018

Condensed Unaudited Financial Statements, Supplemental Guarantor Information [Abstract]

Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss)

CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (in millions)



For the Three Months Ended June 30, 2018	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated MasTec, Inc.
Revenue	$	—		$	1,556.9		$	84.0		$	(23.1	)	$	1,617.8
Costs of revenue, excluding depreciation and amortization	—			1,309.1			80.6			(23.1		)	1,366.6
Depreciation and amortization	—			46.2			5.5			—			51.7
General and administrative expenses	0.8			63.1			3.7			—			67.6
Interest expense (income), net	—			37.1			(16.3		)	—			20.8
Equity in earnings of unconsolidated affiliates	—			—			(5.8		)	—			(5.8		)
Other expense (income), net	—			1.2			(0.4		)	—			0.8
(Loss) income before income taxes	$	(0.8	)	$	100.2		$	16.7		$	—		$	116.2
Benefit from (provision for) income taxes	0.2			(25.9		)	(10.1		)	—			(35.8		)
Net (loss) income before equity in income from subsidiaries	$	(0.6	)	$	74.3		$	6.6		$	—		$	80.4
Equity in income from subsidiaries, net of tax	81.1			—			—			(81.1		)	—
Net income (loss)	$	80.5		$	74.3		$	6.6		$	(81.1	)	$	80.4
Net loss attributable to non-controlling interests	—			—			(0.1		)	—			(0.1		)
Net income (loss) attributable to MasTec, Inc.	$	80.5		$	74.3		$	6.7		$	(81.1	)	$	80.5
Comprehensive income (loss)	$	81.8		$	74.3		$	8.0		$	(82.4	)	$	81.7



For the Three Months Ended June 30, 2017	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated MasTec, Inc.
Revenue	$	—		$	1,820.0		$	85.5		$	(15.3	)	$	1,890.2
Costs of revenue, excluding depreciation and amortization	—			1,557.9			83.7			(15.3		)	1,626.3
Depreciation and amortization	—			38.2			7.2			—			45.4
General and administrative expenses	0.6			66.7			3.5			—			70.8
Interest expense (income), net	—			30.5			(15.7		)	—			14.8
Equity in earnings of unconsolidated affiliates	—			—			(6.1		)	—			(6.1		)
Other (income) expense, net	—			(5.3		)	5.5			—			0.1
(Loss) income before income taxes	$	(0.6	)	$	132.0		$	7.4		$	—		$	138.8
Benefit from (provision for) income taxes	0.2			(47.9		)	(7.7		)	—			(55.4		)
Net (loss) income before equity in income from subsidiaries	$	(0.4	)	$	84.1		$	(0.3	)	$	—		$	83.3
Equity in income from subsidiaries, net of tax	82.1			—			—			(82.1		)	—
Net income (loss)	$	81.7		$	84.1		$	(0.3	)	$	(82.1	)	$	83.3
Net income (loss) attributable to non-controlling interests	—			1.8			(0.1		)	—			1.7
Net income (loss) attributable to MasTec, Inc.	$	81.7		$	82.3		$	(0.2	)	$	(82.1	)	$	81.7
Comprehensive income (loss)	$	79.5		$	84.1		$	(2.5	)	$	(79.9	)	$	81.2



For the Six Months Ended June 30, 2018	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated MasTec, Inc.
Revenue	$	—		$	2,822.5		$	269.6		$	(77.5	)	$	3,014.6
Costs of revenue, excluding depreciation and amortization	—			2,445.3			236.1			(77.5		)	2,603.9
Depreciation and amortization	—			89.5			12.1			—			101.6
General and administrative expenses	1.5			122.4			7.3			—			131.2
Interest expense (income), net	—			70.0			(32.1		)	—			37.9
Equity in earnings of unconsolidated affiliates	—			—			(11.4		)	—			(11.4		)
Other income, net	—			(1.4		)	(0.9		)	—			(2.3		)
(Loss) income before income taxes	$	(1.5	)	$	96.7		$	58.5		$	—		$	153.8
Benefit from (provision for) income taxes	0.4			(24.9		)	(22.3		)	—			(46.9		)
Net (loss) income before equity in income from subsidiaries	$	(1.1	)	$	71.8		$	36.2		$	—		$	106.9
Equity in income from subsidiaries, net of tax	108.2			—			—			(108.2		)	—
Net income (loss)	$	107.1		$	71.8		$	36.2		$	(108.2	)	$	106.9
Net loss attributable to non-controlling interests	—			—			(0.2		)	—			(0.2		)
Net income (loss) attributable to MasTec, Inc.	$	107.1		$	71.8		$	36.4		$	(108.2	)	$	107.1
Comprehensive income (loss)	$	115.5		$	71.8		$	44.7		$	(116.7	)	$	115.3



For the Six Months Ended June 30, 2017	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated MasTec, Inc.
Revenue	$	—		$	2,903.2		$	173.4		$	(28.2	)	$	3,048.4
Costs of revenue, excluding depreciation and amortization	—			2,446.5			179.2			(28.2		)	2,597.5
Depreciation and amortization	—			73.5			14.8			—			88.3
General and administrative expenses	1.2			126.4			8.0			—			135.6
Interest expense (income), net	—			58.4			(31.0		)	—			27.4
Equity in earnings of unconsolidated affiliates	—			—			(7.7		)	—			(7.7		)
Other (income) expense, net	—			(5.3		)	5.9			—			0.6
(Loss) income before income taxes	$	(1.2	)	$	203.7		$	4.2		$	—		$	206.8
Benefit from (provision for) income taxes	0.4			(74.2		)	(9.0		)	—			(82.8		)
Net (loss) income before equity in income from subsidiaries	$	(0.8	)	$	129.5		$	(4.8	)	$	—		$	124.0
Equity in income from subsidiaries, net of tax	123.4			—			—			(123.4		)	—
Net income (loss)	$	122.6		$	129.5		$	(4.8	)	$	(123.4	)	$	124.0
Net income (loss) attributable to non-controlling interests	—			1.6			(0.3		)	—			1.3
Net income (loss) attributable to MasTec, Inc.	$	122.6		$	127.9		$	(4.5	)	$	(123.4	)	$	122.6
Comprehensive income (loss)	$	122.3		$	129.5		$	(5.1	)	$	(123.1	)	$	123.6

Condensed Unaudited Consolidating Balance Sheets

CONDENSED UNAUDITED CONSOLIDATING BALANCE SHEETS (in millions)



As of June 30, 2018	MasTec, Inc.		Guarantor Subsidiaries		Non-Guarantor Subsidiaries		Eliminations			Consolidated MasTec, Inc.
Assets
Total current assets	$	—	$	2,125.9	$	270.4	$	(114.5	)	$	2,281.8
Property and equipment, net	—		687.7		51.7		—			739.4
Goodwill and other intangible assets, net	—		1,193.7		134.4		—			1,328.1
Investments in and advances to consolidated affiliates, net	1,411.8		928.1		831.7		(3,171.6		)	—
Other long-term assets	16.3		34.7		181.8		—			232.8
Total assets	$	1,428.1	$	4,970.1	$	1,470.0	$	(3,286.1	)	$	4,582.2
Liabilities and equity
Total current liabilities	$	—	$	1,200.6	$	166.7	$	(114.5	)	$	1,252.8
Long-term debt	—		1,522.9		10.1		—			1,533.0
Other long-term liabilities	—		352.9		13.1		—			366.0
Total liabilities	$	—	$	3,076.4	$	189.9	$	(114.5	)	$	3,151.8
Total equity	$	1,428.1	$	1,893.7	$	1,280.1	$	(3,171.6	)	$	1,430.4
Total liabilities and equity	$	1,428.1	$	4,970.1	$	1,470.0	$	(3,286.1	)	$	4,582.2



As of December 31, 2017	MasTec, Inc.		Guarantor Subsidiaries		Non-Guarantor Subsidiaries		Eliminations			Consolidated MasTec, Inc.
Assets
Total current assets	$	—	$	1,536.6	$	332.9	$	(17.1	)	$	1,852.4
Property and equipment, net	—		638.7		67.8		—			706.5
Goodwill and other intangible assets, net	—		1,187.9		141.0		—			1,328.9
Investments in and advances to consolidated affiliates, net	1,415.0		847.7		746.6		(3,009.3		)	—
Other long-term assets	15.8		23.4		139.6		—			178.8
Total assets	$	1,430.8	$	4,234.3	$	1,427.9	$	(3,026.4	)	$	4,066.6
Liabilities and equity
Total current liabilities	$	—	$	778.6	$	202.3	$	(17.1	)	$	963.8
Long-term debt	—		1,269.4		11.3		—			1,280.7
Other long-term liabilities	—		379.9		8.8		—			388.7
Total liabilities	$	—	$	2,427.9	$	222.4	$	(17.1	)	$	2,633.2
Total equity	$	1,430.8	$	1,806.4	$	1,205.5	$	(3,009.3	)	$	1,433.4
Total liabilities and equity	$	1,430.8	$	4,234.3	$	1,427.9	$	(3,026.4	)	$	4,066.6

Condensed Unaudited Consolidating Statements of Cash Flows

CONDENSED UNAUDITED CONSOLIDATING STATEMENTS OF CASH FLOWS (in millions)



For the Six Months Ended June 30, 2018	MasTec, Inc.			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations		Consolidated MasTec, Inc.
Net cash (used in) provided by operating activities	$	—		$	(129.6	)	$	152.8		$	—	$	23.2
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired	—			(6.7		)	—			—		(6.7		)
Capital expenditures	—			(85.1		)	(2.9		)	—		(88.0		)
Proceeds from sale of property and equipment	—			12.3			1.6			—		13.9
Payments for other investments	—			(11.2		)	(24.5		)	—		(35.7		)
Proceeds from other investments	—			—			5.4			—		5.4
Net cash used in investing activities	$	—		$	(90.7	)	$	(20.4	)	$	—	$	(111.1	)
Cash flows from financing activities:
Proceeds from credit facilities	—			1,623.3			15.6			—		1,638.9
Repayments of credit facilities	—			(1,357.6		)	(17.0		)	—		(1,374.6		)
Repayments of other borrowings and capital lease obligations	—			(49.9		)	(3.8		)	—		(53.7		)
Payments of acquisition-related contingent consideration	—			(15.9		)	—			—		(15.9		)
Repurchase of common stock	(128.3		)	—			—			—		(128.3		)
Distributions to non-controlling interests	—			(0.6		)	—			—		(0.6		)
Proceeds from stock-based awards, net	1.9			—			—			—		1.9
Net financing activities and advances from (to) consolidated affiliates	126.4			11.8			(138.2		)	—		—
Net cash provided by (used in) financing activities	$	—		$	211.1		$	(143.4	)	$	—	$	67.7
Effect of currency translation on cash	—			—			0.5			—		0.5
Net decrease in cash and cash equivalents	$	—		$	(9.2	)	$	(10.5	)	$	—	$	(19.6	)
Cash and cash equivalents - beginning of period	$	—		$	10.0		$	30.3		$	—	$	40.3
Cash and cash equivalents - end of period	$	—		$	0.8		$	19.8		$	—	$	20.7



For the Six Months Ended June 30, 2017	MasTec, Inc.		Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations		Consolidated MasTec, Inc.
Net cash used in operating activities	$	—	$	(49.9	)	$	(50.3	)	$	—	$	(100.2	)
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired	—		(37.4		)	—			—		(37.4		)
Capital expenditures	—		(55.0		)	(1.9		)	—		(56.9		)
Proceeds from sale of property and equipment	—		6.8			0.6			—		7.4
Payments for other investments	—		(1.2		)	(73.3		)	—		(74.5		)
Proceeds from other investments	—		—			12.1			—		12.1
Net cash used in investing activities	$	—	$	(86.8	)	$	(62.5	)	$	—	$	(149.3	)
Cash flows from financing activities:
Proceeds from credit facilities	—		1,141.2			12.0			—		1,153.2
Repayments of credit facilities	—		(850.2		)	(18.9		)	—		(869.1		)
Repayments of other borrowings and capital lease obligations	—		(36.4		)	(4.7		)	—		(41.1		)
Payments of acquisition-related contingent consideration	—		(6.7		)	—			—		(6.7		)
Distributions to non-controlling interests	—		(1.3		)	—			—		(1.3		)
Proceeds from stock-based awards, net	0.0		—			—			—		0.0
Other financing activities	—		(6.2		)	—			—		(6.2		)
Net financing activities and advances (to) from consolidated affiliates	—		(120.6		)	120.6			—		—
Net cash provided by financing activities	$	—	$	119.8		$	109.0		$	—	$	228.8
Effect of currency translation on cash	—		—			0.1			—		0.1
Net decrease in cash and cash equivalents	$	—	$	(16.9	)	$	(3.7	)	$	—	$	(20.5	)
Cash and cash equivalents - beginning of period	$	—	$	28.9		$	9.9		$	—	$	38.8
Cash and cash equivalents - end of period	$	—	$	12.0		$	6.2		$	—	$	18.2

Business, Basis of Presentation and Significant Accounting Policies (Narrative) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) segment	Jun. 30, 2017	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Number of reportable segments \| segment			5
Revenue [Line Items]
Retained earnings, cumulative effect recognized on intial application of the new guidance	$ 965,768		$ 965,768			$ 857,154
Revenue recognition, performance obligations satisfied in previous periods, revenue recognized	5,200		47,400
Contract with customer, unapproved change orders and/or claims, amount	$ 190,000		$ 190,000			$ 146,000
Maximum [Member]
Revenue [Line Items]
Revenue recognition, changes In contract estimates, cost-to-cost method, financial effect, percentage			5.00%	5.00%
Change order or claim approval process, term within which expected to be completed (in years)			1 year
Maximum [Member] \| Plan [Member]
Revenue [Line Items]
Revenue recognition, performance obligations, completion period (in years)	1 year		1 year
Revenue [Member] \| Concentration Risk from Type of Arrangement [Member] \| Master Service and Other Service Agreements [Member]
Revenue [Line Items]
Concentration risk, percentage of total	37.00%	31.00%	38.00%	37.00%
Revenue [Member] \| Concentration Risk from Type of Arrangement [Member] \| Master Service and Other Service Agreements [Member] \| Point in Time [Member]
Revenue [Line Items]
Concentration risk, percentage of total	7.00%		8.00%
ASU 2014-09 [Member] \| Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue [Line Items]
Retained earnings, cumulative effect recognized on intial application of the new guidance					$ 2,000
ASU 2016-15 [Member]
Revenue [Line Items]
Payments for contingent consideration liabilities, operating activities, reclassification adjustment		$ 12,000

Business, Basis of Presentation and Significant Accounting Policies (Remaining Performance Obligations) (Narrative) (Details) $ in Billions	Jun. 30, 2018 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue recognition, remaining performance obligations, contract price allocated (in dollars)	$ 5.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-07-01
Revenue from Contract with Customer [Abstract]
Revenue recognition, remaining performance obligations, contract price allocated (in dollars)	$ 3.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition, remaining performance obligations, completion period (in months)	6 months

Earnings Per Share (Narrative) (Details) - shares shares in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Earnings Per Share [Line Items]
Computation of earnings per share, methodology		Basic earnings or loss per share is computed by dividing net income or loss attributable to MasTec by the weighted average number of common shares outstanding for the period, which excludes non-participating unvested restricted share awards. Diluted earnings per share is computed by dividing net income or loss attributable to MasTec by the weighted average number of fully diluted shares, as calculated under the treasury stock method, which includes the potential effect of dilutive common stock equivalents, such as issued but unvested restricted shares. If the Company reports a loss, rather than income, the computation of diluted loss per share excludes the effect of dilutive common stock equivalents, as their effect would be anti-dilutive.
Effect of share repurchases, decrease in weighted average shares outstanding (in shares)	2.5	1.4
Treasury Stock, Common [Member]
Earnings Per Share [Line Items]
Treasury stock acquired (in shares)	0.7	2.7

Earnings Per Share (Schedule of Earnings Per Share Information) (Details) - USD ($)
shares in Thousands, $ in Thousands

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Net income attributable to MasTec:

Net income - basic (in dollars)

^[1]

$ 80,492

$ 81,668

$ 107,052

$ 122,638

Net income - diluted (in dollars)

^[1]

$ 80,492

$ 81,668

$ 107,052

$ 122,638

Weighted average shares outstanding:

Weighted average shares outstanding - basic

78,984

80,925

80,061

80,812

Dilutive common stock equivalents (in shares)

1,078

1,367

1,075

1,414

Weighted average shares outstanding - diluted

80,062

82,292

81,136

82,226

Common Stock [Member]

Additional information:

Weighted average anti-dilutive common stock equivalents (in shares)

^[2]

[1]	Calculated as total net income less amounts attributable to non-controlling interests.
[2]	Represents anti-dilutive common stock equivalents as calculated under the treasury stock method.

Goodwill and Other Intangible Assets (Schedule of Goodwill by Segment) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill, gross	$ 1,218,200
Accumulated impairment losses	(71,600)
Goodwill, net	1,146,599	$ 1,137,738
Communications [Member]
Goodwill [Line Items]
Goodwill, gross	467,800
Accumulated impairment losses	0
Goodwill, net	467,800
Oil and Gas [Member]
Goodwill [Line Items]
Goodwill, gross	458,100
Accumulated impairment losses	(71,600)
Goodwill, net	386,500
Electrical Transmission [Member]
Goodwill [Line Items]
Goodwill, gross	149,900
Accumulated impairment losses	0
Goodwill, net	149,900
Power Generation and Industrial [Member]
Goodwill [Line Items]
Goodwill, gross	142,400
Accumulated impairment losses	0
Goodwill, net	$ 142,400

Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Goodwill [Line Items]
Goodwill, additions from new business combinations			$ 9.8
Goodwill, measurement period adjustments			1.6
Amortization expense, intangible assets	$ 5.4	$ 4.9	10.3	$ 9.0
Goodwill, Gross [Member]
Goodwill [Line Items]
Goodwill, currency translation gains (losses)			(5.8)
Goodwill, Accumulated Impairment Loss [Member]
Goodwill [Line Items]
Goodwill, currency translation gains (losses)			$ 3.2

Goodwill and Other Intangible Assets (Rollforward of Other Intangible Assets) (Details) - USD ($)
$ in Thousands

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Dec. 31, 2017

Other intangible assets, gross

$ 356,900

Accumulated amortization

(165,800)

Other intangible assets, net, beginning balance

$ 191,142

Additions from new business combinations, other intangible assets

3,200

Measurement period adjustments, other intangible assets

^[1]

(300)

Amortization expense

$ (5,400)

$ (4,900)

(10,300)

$ (9,000)

Currency translation adjustments, other intangible assets

(2,200)

Other intangible assets, net, ending balance

181,515

Customer Relationships and Backlog [Member]

Other intangible assets, amortizing, gross

223,000

Accumulated amortization

(152,400)

Other intangible assets, net, amortizing, beginning balance

70,600

Additions from new business combinations, amortizing intangible assets

2,900

Measurement period adjustments, amortizing intangible assets

^[1]

400

Amortization expense

(9,500)

Currency translation adjustments, amortizing intangible assets

(200)

Other intangible assets, net, amortizing, ending balance

64,200

Other Amortizing Intangible Assets [Member]

Other intangible assets, amortizing, gross

^[2]

21,800

Accumulated amortization

^[2]

(13,400)

Other intangible assets, net, amortizing, beginning balance

^[2]

8,400

Additions from new business combinations, amortizing intangible assets

^[2]

300

Measurement period adjustments, amortizing intangible assets

^[1],[2]

(700)

Amortization expense

^[2]

(800)

Currency translation adjustments, amortizing intangible assets

^[2]

Other intangible assets, net, amortizing, ending balance

^[2]

7,200

Trade Names [Member]

Other intangible assets, non-amortizing, carrying amount

34,500

Other intangible assets, non-amortizing, beginning balance

34,500

Additions from new business combinations, non-amortizing intangible assets

Measurement period adjustments, non-amortizing intangible assets

^[1]

Currency translation adjustments, non-amortizing intangible assets

Other intangible assets, non-amortizing, ending balance

34,500

Pre-Qualifications [Member]

Other intangible assets, non-amortizing, carrying amount

75,600

77,600

$ 77,600

Other intangible assets, non-amortizing, beginning balance

77,600

Additions from new business combinations, non-amortizing intangible assets

Measurement period adjustments, non-amortizing intangible assets

^[1]

Currency translation adjustments, non-amortizing intangible assets

(2,000)

Other intangible assets, non-amortizing, ending balance

$ 75,600

[1]	Represents adjustments to preliminary estimates of the fair values of intangible assets acquired within the measurement period for the Company’s 2017 acquisitions.
[2]	Consists principally of trade names and non-compete agreements.

Goodwill and Other Intangible Assets (2018 Acquisitions) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2018	Jun. 30, 2018
2018 Power Generation and Industrial Acquisition A [Member]
Business Combinations [Line Items]
Business combinations, percentage of interests acquired		100.00%
Business combinations, description of acquired entity		a construction management firm specializing in steel building systems
2018 Power Generation and Industrial Acquisition B [Member]
Business Combinations [Line Items]
Business combinations, description of acquired entity		a wind turbine services company
2018 Acquisitions [Member]
Business Combinations [Line Items]
Business combinations, cash paid (in dollars)	$ 6.8
Contingent consideration, earn-out liabilities		$ 0.8

Goodwill and Other Intangible Assets (2017 Acquisitions) (Narrative) (Details) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018 USD ($) yr	Dec. 31, 2017 acquisition
Business Combinations [Line Items]
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, low (in dollars)	$ 16
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high (in dollars)	$ 171
Business combinations, contingent consideration liabilities, range of potential earn-out liabilities, maximum unlimited	there is no maximum payment amount
2017 Acquisitions [Member]
Business Combinations [Line Items]
Business combinations, number of acquisitions \| acquisition		3
Business combinations, percentage of interests acquired	100.00%
Business combinations, acquired amortizing intangible assets, weighted average useful life (in years)		10 years
Business combinations, goodwill recognized, description	The goodwill balances for the respective acquisitions represent the estimated value of each acquired company’s geographic presence in key markets, its assembled workforce and management team industry-specific project management expertise, as well as synergies expected to be achieved from the combined operations of the acquired companies and MasTec.
Business combinations, goodwill, expected tax deductible amount (in dollars)	$ 92
Business combinations, contingent consideration, basis for amount	The contingent consideration included in the table above equals a portion of the acquired companies’ earnings before interest, taxes, depreciation and amortization (“EBITDA”), in certain cases in excess of thresholds agreed upon with the sellers, if applicable, for a period of five years, as set forth in the respective purchase agreements, which amounts are payable annually.
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, low (in dollars)	$ 10
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high (in dollars)	$ 161
Business combinations, contingent consideration liabilities, range of potential earn-out liabilities, maximum unlimited	there is no maximum payment amount
2017 Acquisitions [Member] \| Expected Term [Member]
Business Combinations [Line Items]
Business combinations, contingent consideration, earn-out period (in years) \| yr	5
2017 Acquisitions [Member] \| Customer Relationships [Member]
Business Combinations [Line Items]
Business combinations, acquired amortizing intangible assets, weighted average useful life (in years)		11 years
2017 Acquisitions [Member] \| Backlog [Member]
Business Combinations [Line Items]
Business combinations, acquired amortizing intangible assets, weighted average useful life (in years)		4 years
2017 Acquisitions [Member] \| Other Amortizing Intangible Assets [Member]
Business Combinations [Line Items]
Business combinations, acquired amortizing intangible assets, weighted average useful life (in years)		6 years
2017 Communications Acquisition [Member]
Business Combinations [Line Items]
Business combinations, description of acquired entity	a wireline/fiber deployment construction contractor
2017 Power Generation and Industrial Acquisition [Member]
Business Combinations [Line Items]
Business combinations, description of acquired entity	a heavy civil construction services company
2017 Oil and Gas Acquisition [Member]
Business Combinations [Line Items]
Business combinations, description of acquired entity	an oil and gas pipeline equipment company

Goodwill and Other Intangible Assets (Schedule of Consideration Paid and Net Assets Acquired, Business Combinations) (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Acquisition consideration:
Fair value of contingent consideration (earn-out liability)	$ 3,510	$ 25,000
Identifiable assets acquired and liabilities assumed:
Goodwill	$ 1,146,599		$ 1,137,738
2017 Acquisitions [Member]
Acquisition consideration:
Cash			120,400
Fair value of contingent consideration (earn-out liability)			96,300
Total consideration transferred			216,700
Identifiable assets acquired and liabilities assumed:
Current assets, primarily composed of accounts receivable and $2.8 million of cash acquired			43,800
Cash acquired			2,800
Property and equipment and other long-term assets			57,200
Amortizing intangible assets			28,100
Current liabilities, including current portion of capital lease obligations and long-term debt			(29,500)
Long-term debt, including capital lease obligations			(9,900)
Deferred income taxes and other long-term liabilities			(12,000)
Total identifiable net assets			77,700
Goodwill			139,000
Total net assets acquired, including goodwill			$ 216,700

Goodwill and Other Intangible Assets (Unaudited Pro Forma Financial Information) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Business Combinations, Unaudited Pro Forma Information [Abstract]
Business combinations, unaudited pro forma revenue	$ 1,617.4	$ 1,924.0	$ 3,017.7	$ 3,144.2
Business combinations, unaudited pro forma net income	80.6	84.7	$ 104.7	127.1
Business combinations, unaudited pro forma information, description			These unaudited pro forma financial results represent the results of operations of the companies acquired as if the acquired companies had been consolidated as of the beginning of the year prior to their acquisition, and are provided for illustrative purposes only. These unaudited pro forma financial results do not purport to be indicative of the actual results that would have been achieved by the combined companies for the periods indicated, or of the results that may be achieved by the combined companies in the future. The Company’s unaudited pro forma financial results were prepared by adjusting the historical results of MasTec to include the historical results of the acquired businesses described above, and then adjusted for (i) acquisition costs; (ii) amortization expense resulting from the acquired intangible assets; (iii) interest expense as a result of the cash consideration paid; (iv) interest expense from debt repaid upon acquisition; and (iv) elimination of the effects of intercompany transactions and other purchase accounting related adjustments. These unaudited pro forma financial results do not include adjustments to reflect other cost savings or synergies that may have resulted from these acquisitions.
Business combinations, acquisition-related results, revenue	45.7	33.9	$ 122.6	33.9
Business combinations, acquisition-related results, net income	$ 0.5	$ 1.6	$ 2.5	$ 1.6

Fair Value of Financial Instruments (Acquisition-Related Contingent Consideration) (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, low	$ 16,000,000		$ 16,000,000
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high	171,000,000		$ 171,000,000
Acquisition-related contingent consideration liabilities, range of potential earn-out liabilities, maximum unlimited			there is no maximum payment amount
Acquisition-related contingent consideration liabilities, (decrease) increase, measurement period adjustments			$ 1,600,000
Earn-Out Liabilities [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, estimated fair value	102,000,000		102,000,000		$ 117,200,000
Acquisition-related contingent consideration liabilities, additions from new business combinations	0	$ 25,000,000	1,500,000	$ 25,000,000
Acquisition-related contingent consideration liabilities, (decrease) increase, measurement period adjustments	(700,000)		2,000,000
Acquisition-related contingent consideration liabilities, increase (decrease), loss (gain) recorded in earnings	4,400,000	(8,600,000)	4,400,000	(8,600,000)
Acquisition-related contingent consideration liabilities, payments	23,100,000	$ 18,800,000	23,100,000	$ 18,800,000
Earn-Out Liabilities [Member] \| Other Current Liabilities [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, estimated fair value	$ 26,000,000		$ 26,000,000		$ 22,600,000

Fair Value of Financial Instruments (Equity Investments) (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investment, adjusted cost basis, amount	$ 18	$ 18
Equity Investee [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Carrying value, equity investments	190	141
CCI [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investment, adjusted cost basis, amount	$ 15
Waha JVs [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investment, ownership percentage	33.00%
Waha JVs [Member] \| Equity Investee [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Carrying value, equity investments	$ 160	$ 121

Fair Value of Financial Instruments (The Waha JVs) (Narrative) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) pipeline	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) pipeline	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, equity in earnings (losses)	$ 5,824,000	$ 6,060,000	$ 11,409,000	$ 7,706,000
Unrealized gains (losses) on equity method investee activity, net of tax	2,937,000	(2,730,000)	10,653,000	(2,095,000)
Equity Investee [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, net investment	190,000,000		190,000,000		$ 141,000,000
Credit Facility [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Letters of credit issued	$ 124,700,000		$ 124,700,000		157,100,000
Waha JVs [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Number of pipelines in operation \| pipeline	2		2
Equity method investments, equity contributions	$ 9,700,000	19,900,000	$ 24,500,000	73,300,000
Equity method investments, equity in earnings (losses)	5,800,000	6,100,000	11,400,000	7,700,000
Equity method investments, cumulative undistributed earnings	20,600,000		20,600,000
Equity method investments, distributions of earnings received	2,000,000		7,700,000
Revenue, related parties		100,200,000		251,600,000
Receivables, net of BIEC, related parties	200,000		200,000		2,800,000
Unrealized gains (losses) on equity method investee activity	3,900,000	(4,400,000)	14,000,000	(3,400,000)
Unrealized gains (losses) on equity method investee activity, net of tax	2,900,000	$ (2,700,000)	10,700,000	$ (2,100,000)
Waha JVs [Member] \| Equity Investee [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, net investment	160,000,000		160,000,000		121,000,000
Waha JVs [Member] \| Credit Facility [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Letters of credit issued	$ 0		$ 0		$ 19,000,000

Fair Value of Financial Instruments (Other Investments - Pensare) (Narrative) (Details) - Pensare [Member] $ / shares in Units, warrant in Millions, $ in Millions		3 Months Ended
	Jun. 30, 2018 warrant $ / shares	Sep. 30, 2017 USD ($)
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investment and warrants, amount paid (in dollars) \| $		$ 2.0
Equity investment, ownership percentage	4.00%
Derivative instruments, number held \| warrant	2.0
Plan [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Warrants, exercise price (in dollars per share) \| $ / shares	$ 11.50
Plan [Member] \| Common Stock [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Investment, restriction period (in years)	1 year

Fair Value of FInancial Instruments (Other Investments - Lifeshield) (Narrative) (Details) - Lifeshield [Member] $ in Millions	Jun. 30, 2018 USD ($)
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Fair value investment, carrying amount	$ 10.0
Fair value investment, ownership percentage	38.50%

Fair Value of Financial Instruments (Other Investments - Pacer) (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Other investment, proceeds related to ongoing liquidation					$ 5,415	$ 12,118
Other investment, net carrying value	$ 40,152				40,152		$ 35,763
Pacer [Member] \| Investments [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Other investment, changes in expected recovery estimates, expense	900		$ 5,800
Other investment, proceeds related to ongoing liquidation		$ 5,400		$ 12,100
Other investment, net carrying value	$ 3,000				$ 3,000		$ 9,600

Fair Value of Financial Instruments (Senior Notes) (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
4.875% Senior Notes, gross carrying amount	$ 400.0	$ 400.0
Senior Notes [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
4.875% Senior Notes, estimated fair value	$ 392.0	$ 410.0
4.875% Senior Notes [Member] \| Senior Notes [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Debt instrument, interest rate (percentage)	4.875%

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities (Schedule of Accounts Receivable, Net of Allowance and Contract Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Accounts Receivable, Net of Allowance, and Contract Assets [Abstract]
Contract billings	$ 561,600	$ 683,900
Less allowance for doubtful accounts	(9,500)	(8,200)
Accounts receivable, net of allowance	552,100	675,700
Retainage	317,900	323,100
Costs and earnings in excess of billings	1,207,500	599,200
Retainage and costs and earnings in excess of billings (together, “contract assets”)	1,525,400	922,300
Accounts receivable, net	$ 2,077,487	$ 1,598,015

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Billings in excess of costs and earnings	$ 243,224		$ 243,224		$ 194,494
Revenue recognition, BIEC, revenue recognized	15,000		99,800
Contract liabilities	251,100		251,100		$ 206,100
Provisions for doubtful accounts	500	$ 200	$ 1,400	$ 700
Retainage, expected collection period (in years)			1 year
Interest Expense [Member] \| Accounts Receivable Financing Arrangements [Member]
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Non-recourse financing arrangements, discount charge	$ 3,100	$ 1,700	$ 5,000	$ 2,600
Minimum [Member]
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Retainage, percent of contract billings			5.00%
Maximum [Member]
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Retainage, percent of contract billings			10.00%

Property and Equipment, Net (Schedule of Property and Equipment, Net) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Property and Equipment [Line Items]
Property and equipment	$ 1,536,000	$ 1,455,600
Less accumulated depreciation and amortization	(796,600)	(749,100)
Property and equipment, net	739,425	706,506
Land [Member]
Property and Equipment [Line Items]
Property and equipment	4,600	4,600
Building and Leasehold Improvements [Member]
Property and Equipment [Line Items]
Property and equipment	28,400	26,700
Machinery and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment	1,319,500	1,261,900
Office Furniture and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment	157,300	149,900
Construction in Progress [Member]
Property and Equipment [Line Items]
Property and equipment	$ 26,200	$ 12,500

Property and Equipment, Net (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Property and Equipment [Line Items]
Capitalized internal-use software, gross	$ 115,800		$ 115,800		$ 109,900
Capitalized internal-use software, net	25,000		25,000		$ 23,500
Depreciation and amortization	51,676	$ 45,379	101,615	$ 88,282
Property and Equipment [Member]
Property and Equipment [Line Items]
Depreciation and amortization	$ 46,300	$ 40,500	$ 91,300	$ 79,200

Debt (Schedule of Carrying Values of Debt) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Capital lease obligations	$ 182,600	$ 181,200
Total long-term debt obligations	1,628,700	1,381,600
Less unamortized deferred financing costs	(11,500)	(13,000)
Total debt, net of deferred financing costs	1,617,200	1,368,600
Current portion of long-term debt	84,215	87,866
Long-term debt	$ 1,532,978	1,280,706
Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maturity date	Feb. 22, 2022
Credit Facility [Member] \| Revolving Loans [Member]
Debt Instrument [Line Items]
Long-term debt obligations	$ 648,100	377,700
Credit Facility [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Long-term debt obligations	386,900	396,900
Senior Notes [Member] \| 4.875% Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt obligations	$ 400,000	400,000
Debt instrument, interest rate (percentage)	4.875%
Debt instrument, maturity date	Mar. 15, 2023
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Debt instrument, weighted average interest rate (percentage)	3.80%
Capital lease obligations, expiration date, range, end	May 01, 2023
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Long-term debt obligations	$ 11,100	$ 25,800

Debt (Senior Secured Credit Facility) (Narrative) (Details) - Credit Facility [Member] - USD ($) $ in Millions			1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2017	Mar. 31, 2018	Jun. 30, 2018
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,500.0				$ 1,500.0
Line of credit facility, letters of credit issued	$ 124.7	$ 157.1	$ 157.1		$ 124.7
Line of credit facility, unused facility fee (percentage)	0.30%	0.25%
Line of credit facility, collateral, description					The Credit Facility is guaranteed by certain subsidiaries of the Company (the “Guarantor Subsidiaries”) and the obligations under the Credit Facility are secured by substantially all of the Company’s and the Guarantor Subsidiaries’ respective assets, subject to certain exceptions.
Revolving Loans [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,100.0				$ 1,100.0
Line of credit facility, amount of borrowings denominated in foreign currencies	106.0	$ 117.0	117.0		106.0
Line of credit facility, remaining borrowing capacity	327.2	565.2	565.2		327.2
Line of credit facility, remaining borrowing capacity available in either Canadian dollars or Mexican pesos	$ 194.4	$ 183.4	$ 183.4		$ 194.4
Revolving Loans [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	3.91%	3.69%	3.69%		3.91%
Term Loan [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 400.0				$ 400.0
Line of credit facility, term loan, frequency of payments					quarterly
Line of credit facility, term loan, amount of quarterly principal installment payments			$ 3.1	$ 5.0
Line of credit facility, interest rate (percentage)	3.72%	3.07%	3.07%		3.72%
Letters of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, capacity available for letters of credit	$ 327.2	$ 492.9	$ 492.9		$ 327.2
Letters of Credit [Member] \| Performance Standby [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	0.75%	0.625%	0.625%		0.75%
Letters of Credit [Member] \| Commercial and/or Financial Standby [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	1.625%	1.50%	1.50%		1.625%

Debt (Other Credit Facilities) (Narrative) (Details) - Other Credit Facilities [Member] $ in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2018 CAD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2017 CAD ($)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity (in dollars)	$ 20.0		$ 20.0
Debt instrument, rationale for classification as long-term debt	Outstanding borrowings that are not renewed are repaid with borrowings under the Credit Facility. Accordingly, the carrying amounts of the Company’s borrowings under its other credit facilities, which are included within other debt obligations in the table above, are classified within long-term debt in the Company’s consolidated balance sheets.
Weighted Average [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	4.20%	4.20%	4.00%	4.00%
Canadian Dollars [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity (in dollars)		$ 15.2		$ 15.9
Long-term debt obligations (in dollars)		$ 9.2		$ 10.4

Debt (Debt Guarantees and Covenants) (Narrative) (Details) - Senior Notes [Member] - 4.875% Senior Notes [Member]	6 Months Ended
	Jun. 30, 2018
Debt Instrument [Line Items]
Debt instrument, guarantees, description	The 4.875% Senior Notes are senior unsecured unsubordinated obligations and rank equal in right of payment with existing and future unsubordinated debt, and rank senior in right of payment to existing and future subordinated debt and are fully and unconditionally guaranteed on an unsecured, unsubordinated, joint and several basis by certain of the Company’s existing and future 100%-owned direct and indirect domestic subsidiaries that are each guarantors of the Credit Facility or other outstanding indebtedness.
Debt instrument, interest rate (percentage)	4.875%

Debt (Additional Information) (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Senior Notes [Member] \| 4.875% Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate (percentage)	4.875%
Other Accrued Expenses [Member]
Debt Instrument [Line Items]
Debt instruments, accrued interest payable (in dollars)	$ 8.2	$ 7.4

Lease Obligations (Capital Leases) (Narrative) (Details) - Property and Equipment [Member] - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Capital Leases [Line Items]
Assets held under capital lease, gross	$ 432.4	$ 418.0
Assets held under capital lease, net	$ 287.4	$ 277.3

Lease Obligations (Operating Leases) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Lease Term in Excess of One Year [Member]
Operating Leased Assets [Line Items]
Operating leases, rent and related expense (in dollars)	$ 25.3	$ 26.6	$ 52.2	$ 52.2
Lease Term in Excess of One Year [Member] \| Minimum [Member]
Operating Leased Assets [Line Items]
Operating leases, term of contract (in years)	1 year	1 year	1 year	1 year
Lease Term of One Year or Less [Member]
Operating Leased Assets [Line Items]
Operating leases, rent and related expense (in dollars)	$ 104.9	$ 133.3	$ 196.6	$ 188.4
Lease Term of One Year or Less [Member] \| Maximum [Member]
Operating Leased Assets [Line Items]
Operating leases, term of contract (in years)	1 year	1 year	1 year	1 year

Stock-Based Compensation and Other Employee Benefit Plans (Narrative) (Details)	Jun. 30, 2018 shares
Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation, number of shares available for future grant	4,675,000

Stock-Based Compensation and Other Employee Benefit Plans (Restricted Shares) (Narrative) (Details) - Restricted Shares [Member] - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation awards, unearned compensation	$ 19.7	$ 19.7		$ 19.7
Stock-based compensation awards, unearned compensation, weighted average expected recognition period (in years)	2 years
Stock-based compensation, vested awards, intrinsic value		$ 1.6	$ 0.2	$ 1.7	$ 11.7

Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Activity, Restricted Shares) (Details) - Common Stock [Member]

6 Months Ended

Jun. 30, 2018

$ / shares

Restricted Shares [Member]

Restricted Shares

Non-vested restricted shares, beginning balance (in shares)

1,448,591

^[1]

Granted (in shares)

116,822

Vested (in shares)

(36,477)

Canceled/forfeited (in shares)

(29,054)

Non-vested restricted shares, ending balance (in shares)

1,499,882

^[1]

Per Share Weighted Average Grant Date Fair Value

Non-vested restricted shares, per share weighted average grant date fair value, beginning balance (in dollars per share) | $ / shares

$ 23.29

Granted (in dollars per share) | $ / shares

50.67

Vested (in dollars per share) | $ / shares

21.85

Canceled/forfeited (in dollars per share) | $ / shares

20.65

Non-vested restricted shares, per share weighted average grant date fair value, ending balance (in dollars per share) | $ / shares

$ 25.51

Restricted Stock Units [Member]

Restricted Shares

Non-vested restricted shares, beginning balance (in shares)

27,550

Non-vested restricted shares, ending balance (in shares)

19,300

[1]	Includes 19,300 and 27,550 restricted stock units as of June 30, 2018 and December 31, 2017, respectively.

Stock-Based Compensation and Other Employee Benefit Plans (Employee Stock Purchase Plans) (Narrative) (Details)	6 Months Ended
	Jun. 30, 2018
Employee Stock Purchase Plans [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plans, description	The Company has certain employee stock purchase plans (collectively, “ESPPs”) under which shares of the Company's common stock are available for purchase by eligible employees.

Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Employee Stock Purchase Plans) (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Common shares issued (in shares)	55,138	49,502
Employee Stock Purchase Plans [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Cash proceeds (in dollars)	$ 2.2	$ 1.6
Employee Stock Purchase Plans [Member] \| Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Weighted average price per share (in dollars per share)	$ 39.99	$ 33.30
Weighted average per share grant date fair value (in dollars per share)	$ 9.74	$ 8.67

Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Non-Cash Stock-Based Compensation Expense and Related Tax Effects) (Details) - USD ($)
$ in Thousands

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Stock-Based Compensation and Other Employee Benefit Plans [Line Items]

Non-cash stock-based compensation expense

$ 6,571

$ 7,166

Income Tax Effects:

Income tax effect of non-cash stock-based compensation

$ 1,000

$ 1,300

1,800

2,500

Excess tax benefit from non-cash stock-based compensation

^[1]

200

100

Tax benefits (deficiencies), net

(35,782)

(55,434)

(46,908)

(82,792)

Share-Based Compensation [Member]

Income Tax Effects:

Tax benefits (deficiencies), net

200

(100)

General and Administrative Expenses [Member]

Stock-Based Compensation and Other Employee Benefit Plans [Line Items]

Non-cash stock-based compensation expense

$ 3,400

$ 6,600

$ 7,200

[1]

Other Retirement Plans (Narrative) (Details)	6 Months Ended
Other Retirement Plans (Narrative) (Details)	Jun. 30, 2018
Multiemployer Plans [Abstract]
Multiemployer plans, general nature	Certain of MasTec’s subsidiaries, including certain subsidiaries in Canada, contribute amounts to multiemployer pension and other multiemployer benefit plans and trusts (“MEPPs”), which are recorded as a component of employee wages and salaries within costs of revenue, excluding depreciation and amortization. Contributions are generally based on fixed amounts per hour per employee for employees covered under these plans. Multiemployer plan contribution rates are determined annually and assessed on a “pay-as-you-go” basis based on union employee payrolls.

Other Retirement Plans (Schedule of Covered Employees and Contributions, Multiemployer Plans) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) employee	Jun. 30, 2017 USD ($) employee	Jun. 30, 2018 USD ($) employee	Jun. 30, 2017 USD ($) employee
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer plans, contributions (in dollars)	$ 21.8	$ 31.0	$ 35.1	$ 37.3
Multiemployer Plans, Pension [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer plans, contributions (in dollars)	19.7	28.3	31.0	32.0
Multiemployer Plans, Other Multiemployer [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer plans, contributions (in dollars)	$ 2.1	$ 2.7	$ 4.1	$ 5.3
Workforce Subject to Collective Bargaining Arrangements [Member] \| Unionized Employees [Member] \| Low [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer plans, covered employees (in number of employees) \| employee	2,612	3,669	2,018	550
Workforce Subject to Collective Bargaining Arrangements [Member] \| Unionized Employees [Member] \| High [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer plans, covered employees (in number of employees) \| employee	6,183	7,057	6,183	7,057

Equity (Share Activity) (Narrative) (Details) - USD ($) shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2018
Equity, Treasury Stock [Line Items]
Treasury stock acquired, value	$ 29,900,000		$ 128,300,000
2016 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired, value		$ 98,400,000
2018 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Share repurchase program, amount authorized, value		$ 100,000,000
Share repurchase program, amount available for future share repurchases, value	$ 70,000,000		$ 70,000,000
Treasury Stock, Common [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)	0.7		2.7
Treasury Stock, Common [Member] \| 2016 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)		2.0
Treasury Stock, Common [Member] \| 2018 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)	0.7

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	12 Months Ended
Income Taxes (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Quarterly provision for income taxes, description			In determining the quarterly provision for income taxes, management uses an estimated annual effective tax rate based on forecasted annual pre-tax income, permanent tax differences, statutory tax rates and tax planning opportunities in the various jurisdictions in which the Company operates. The effect of significant discrete items is separately recognized in the quarter(s) in which they occur.
U.S. corporate tax rate (percentage)			21.00%	35.00%
Change in tax rate, non-cash tax benefit (expense) (in dollars)	$ (1.5)	$ 120.1

Segments and Related Information (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($) segment	Jun. 30, 2017 USD ($)
Segments and Related Information [Line Items]
Segment reporting information, factors used to identify entity's reportable segments	MasTec manages its operations under five operating segments, which represent MasTec’s five reportable segments: (1) Communications; (2) Oil and Gas; (3) Electrical Transmission; (4) Power Generation and Industrial and (5) Other. This structure is generally focused on broad end-user markets for MasTec’s labor-based construction services.
Number of operating segments	5
Number of reportable segments	5
Segment reporting information, description of products and services	All five reportable segments derive their revenue from the engineering, installation and maintenance of infrastructure, primarily in North America.
Segment reporting, description of all other segments	The Other segment includes equity investees, the services of which vary from those provided by the Company’s four primary segments, as well as other small business units that perform construction and other services for a variety of international end-markets.
Communications [Member]
Segments and Related Information [Line Items]
Segment reporting information, description of products and services	The Communications segment performs engineering, construction, maintenance and customer fulfillment activities related to communications infrastructure primarily for wireless and wireline/fiber communications and install-to-the-home customers, and, to a lesser extent, infrastructure for utilities, among others.
Oil and Gas [Member]
Segments and Related Information [Line Items]
Segment reporting information, description of products and services	MasTec performs engineering, construction and maintenance services on oil and natural gas pipelines and processing facilities for the energy and utilities industries through its Oil and Gas segment.
Electrical Transmission [Member]
Segments and Related Information [Line Items]
Segment reporting information, description of products and services	The Electrical Transmission segment primarily serves the energy and utility industries through the engineering, construction and maintenance of electrical transmission lines and substations.
Power Generation and Industrial [Member]
Segments and Related Information [Line Items]
Segment reporting information, description of products and services	The Power Generation and Industrial segment primarily serves energy, utility and other end-markets through the installation and construction of conventional and renewable power facilities, related electrical transmission infrastructure, ethanol/biofuel facilities and various types of heavy civil and industrial infrastructure.
Primary Segments [Member]
Segments and Related Information [Line Items]
Number of operating segments	4
Joint Venture [Member] \| Pacer [Member]
Segments and Related Information [Line Items]
Project gains \| $	$ 1.0
Project losses \| $		$ 7.0

Segments and Related Information (Schedule of Financial Information by Reportable Segment - Revenue) (Details) - USD ($)
$ in Thousands

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Revenue:

Communications [Member] | Customer Concentration Risk [Member] | Revenue [Member] | Utilities [Member]

$ 1,617,804

$ 1,890,180

$ 3,014,638

$ 3,048,364

Revenue:

Utilities customers, percentage of Communications segment revenue

13.60%

11.50%

15.70%

12.40%

Reportable Segments [Member] | Communications [Member]

Revenue:

Reportable Segments [Member] | Oil and Gas [Member]

^[1]

$ 618,600

$ 592,200

$ 1,245,700

$ 1,151,700

Revenue:

Reportable Segments [Member] | Electrical Transmission [Member]

769,300

1,140,400

1,305,800

1,596,200

Revenue:

Reportable Segments [Member] | Power Generation and Industrial [Member]

84,500

96,600

198,500

195,400

Revenue:

Reportable Segments [Member] | Other [Member]

146,000

60,700

263,600

107,300

Revenue:

200

1,900

2,200

3,600

Eliminations [Member]

Revenue:

AT&T (including DIRECTV) [Member]

$ (800)

$ (1,600)

$ (1,200)

$ (5,800)

[1]	Revenue generated primarily by utilities customers represented 13.6% and 11.5% of Communications segment revenue for the three month periods ended June 30, 2018 and 2017, respectively, and represented 15.7% and 12.4% for the six month periods ended June 30, 2018 and 2017, respectively.

Segments and Related Information (Schedule of Financial Information by Reportable Segment - EBITDA) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
EBITDA:
EBITDA	$ 188.7	$ 198.9	$ 293.2	$ 322.4
Reportable Segments [Member] \| Communications [Member]
EBITDA:
EBITDA	73.7	59.5	155.8	107.8
Reportable Segments [Member] \| Oil and Gas [Member]
EBITDA:
EBITDA	122.7	154.0	155.7	247.9
Reportable Segments [Member] \| Electrical Transmission [Member]
EBITDA:
EBITDA	(2.7)	3.5	1.9	6.7
Reportable Segments [Member] \| Power Generation and Industrial [Member]
EBITDA:
EBITDA	9.8	4.7	14.6	5.6
Reportable Segments [Member] \| Other [Member]
EBITDA:
EBITDA	6.8	6.8	12.7	1.5
Corporate [Member]
EBITDA:
EBITDA	$ (21.6)	$ (29.6)	$ (47.5)	$ (47.1)

Segments and Related Information (Schedule of Financial Information by Reportable Segment - Depreciation and Amortization) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Depreciation and Amortization:
Depreciation and amortization	$ 51,676	$ 45,379	$ 101,615	$ 88,282
Reportable Segments [Member] \| Communications [Member]
Depreciation and Amortization:
Depreciation and amortization	15,300	13,500	29,900	25,500
Reportable Segments [Member] \| Oil and Gas [Member]
Depreciation and Amortization:
Depreciation and amortization	26,100	23,200	51,600	45,100
Reportable Segments [Member] \| Electrical Transmission [Member]
Depreciation and Amortization:
Depreciation and amortization	5,100	5,700	10,400	11,400
Reportable Segments [Member] \| Power Generation and Industrial [Member]
Depreciation and Amortization:
Depreciation and amortization	3,600	1,400	6,600	2,900
Reportable Segments [Member] \| Other [Member]
Depreciation and Amortization:
Depreciation and amortization	0	0	100	100
Corporate [Member]
Depreciation and Amortization:
Depreciation and amortization	$ 1,600	$ 1,600	$ 3,000	$ 3,300

Segments and Related Information (Reconciliation of Consolidated Income before Income Taxes to EBITDA) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
EBITDA Reconciliation:
Income before income taxes	$ 116,183	$ 138,766	$ 153,772	$ 206,751
Interest expense, net	20,795	14,791	37,854	27,388
Depreciation and amortization	51,676	45,379	101,615	88,282
Consolidated EBITDA	$ 188,700	$ 198,900	$ 293,200	$ 322,400

Segments and Related Information (Foreign Operations) (Narrative) (Details) - USD ($) $ in Thousands			3 Months Ended		6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segments and Related Information [Line Items]
Revenue			$ 1,617,804	$ 1,890,180	$ 3,014,638	$ 3,048,364
Property and equipment, net	$ 739,425	$ 706,506	739,425		739,425
Intangible assets and goodwill, net	1,328,100	1,328,900	1,328,100		1,328,100
United States [Member]
Segments and Related Information [Line Items]
Revenue			1,600,000	1,800,000	3,000,000	2,900,000
Property and equipment, net	698,600	649,500	698,600		698,600
Intangible assets and goodwill, net	1,200,000	1,200,000	1,200,000		1,200,000
Foreign Operations [Member]
Segments and Related Information [Line Items]
Revenue			26,700	$ 40,500	60,500	$ 99,700
Property and equipment, net	40,800	57,000	40,800		40,800
Intangible assets and goodwill, net	$ 107,000	$ 112,800	$ 107,000		$ 107,000
Foreign Operations [Member] \| Accounts Receivable, Net, Less BIEC [Member] \| Geographic Concentration Risk [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total	3.00%	5.00%

Segments and Related Information (Schedule of Significant Customers, Revenue Concentration Information) (Details) - Customer Concentration Risk [Member] - Revenue [Member]

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Revenue, Significant Customers [Line Items]

Concentration risk, percentage of total

^[1]

25.00%

22.00%

26.00%

27.00%

Energy Transfer Affiliates [Member]

Revenue, Significant Customers [Line Items]

Concentration risk, percentage of total

^[2]

15.00%

47.00%

20.00%

35.00%

EQT Corporation [Member]

Revenue, Significant Customers [Line Items]

Concentration risk, percentage of total

^[3]

19.00%

0.00%

11.00%

0.00%

[1]	The Company’s relationship with AT&T is based upon multiple separate master service and other service agreements, including for installation and maintenance services, as well as construction/installation contracts for AT&T’s: (i) wireless business; (ii) wireline/fiber businesses; and (iii) various install-to-the-home businesses, including DIRECTV®. Revenue from AT&T is included in the Communications segment.
[2]	The Company's relationship with Energy Transfer affiliates is based upon various construction contracts for pipeline activities with Energy Transfer Partners L.P., and its subsidiaries and affiliates, all of which are consolidated by Energy Transfer Equity, L.P. Revenue from Energy Transfer affiliates is included in the Oil and Gas segment.
[3]	The Company's relationship with EQT Corporation and its affiliates is based upon various construction contracts for pipeline activities. Revenue from EQT Corporation is included in the Oil and Gas segment.

Commitments and Contingencies (Other Commitments and Contingencies) (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Self-Insurance [Member] \| Workers' Compensation, General and Automobile Policies [Member]
Commitments and Contingencies [Line Items]
Self-insurance reserve	$ 101.7	$ 106.2
Self-Insurance [Member] \| Workers' Compensation, General and Automobile Policies [Member] \| Other Long-Term Liabilities [Member]
Commitments and Contingencies [Line Items]
Self-insurance reserve, non-current	65.6	72.2
Self-Insurance [Member] \| Workers' Compensation, General and Automobile Policies [Member] \| Other Long-Term Assets [Member] \| Cash [Member]
Commitments and Contingencies [Line Items]
Cash collateral held by insurance carriers	1.6	1.6
Self-Insurance [Member] \| Employee Group Medical Claims Policies [Member]
Commitments and Contingencies [Line Items]
Self-insurance reserve	2.5	2.6
Performance and Payment Bonds [Member]
Commitments and Contingencies [Line Items]
Bonded projects, estimated costs to complete	43.8	46.0
Performance and Payment Bonds [Member] \| Subsidiaries [Member]
Commitments and Contingencies [Line Items]
Outstanding bonds, amount	108.6	119.7
Surety Bond [Member] \| Self-Insurance [Member] \| Workers' Compensation [Member]
Commitments and Contingencies [Line Items]
Outstanding bonds, amount	15.2	15.2
Credit Facility [Member]
Commitments and Contingencies [Line Items]
Letters of credit issued	124.7	157.1
Credit Facility [Member] \| Financial Guarantees [Member] \| Self-Insurance [Member] \| Workers' Compensation, General and Automobile Policies [Member]
Commitments and Contingencies [Line Items]
Letters of credit issued	$ 87.8	$ 88.9

Commitments and Contingencies (Investment Arrangements) (Narrative) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Other Commitments [Line Items]
Cash, amounts held by proportionately consolidated non-controlled joint ventures	$ 20,684	$ 40,326	$ 18,230	$ 38,767
Current liabilities, amounts due by proportionately consolidated non-controlled contractual joint ventures	84,899	65,455
Joint Venture [Member]
Other Commitments [Line Items]
Cash, amounts held by proportionately consolidated non-controlled joint ventures	17,900	$ 17,300
Joint Venture [Member] \| Advances on Project Work [Member]
Other Commitments [Line Items]
Current liabilities, amounts due by proportionately consolidated non-controlled contractual joint ventures	$ 10,300
Joint Venture [Member] \| Pacer [Member]
Other Commitments [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage	35.00%
Joint Venture [Member] \| Joint Ventures That Provide Electrical Transmission Infrastructure Services [Member] \| Minimum [Member]
Other Commitments [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage	85.00%
Joint Venture [Member] \| Joint Ventures That Provide Electrical Transmission Infrastructure Services [Member] \| Maximum [Member]
Other Commitments [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage	90.00%

Commitments and Contingencies (Other Guarantees) (Narrative) (Details)	6 Months Ended
	Jun. 30, 2018
Other Guarantees [Line Items]
General warranty, description	MasTec also generally warrants the work it performs for a one to two year period following substantial completion of a project. Much of the work performed by the Company is evaluated for defects shortly after the work is completed.
Minimum [Member]
Other Guarantees [Line Items]
General warranty, period (in years)	1 year
Maximum [Member]
Other Guarantees [Line Items]
General warranty, period (in years)	2 years
Subsidiaries [Member]
Other Guarantees [Line Items]
Other guarantees, description	In the ordinary course of its business, from time to time, MasTec guarantees the obligations of its subsidiaries, including obligations under certain contracts with customers, certain lease obligations and in some states, obligations in connection with obtaining contractors’ licenses.

Commitments and Contingencies (Concentrations of Risk) (Narrative) (Details) - customer			3 Months Ended		6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Concentration Risk [Line Items]
Number of customers					395
Accounts Receivable, Net, Less BIEC [Member] \| Credit Concentration Risk [Member] \| Disclosed Customers with Highest Net Accounts Receivable Positions [Member]
Concentration Risk [Line Items]
Number of customers	3	2
Accounts Receivable, Net, Less BIEC [Member] \| Credit Concentration Risk [Member] \| Customer with Highest Net Accounts Receivable Position [Member]
Concentration Risk [Line Items]
Concentration risk, percentage of total	39.00%	46.00%
Accounts Receivable, Net, Less BIEC [Member] \| Credit Concentration Risk [Member] \| Customer with Second Highest Net Accounts Receivable Position [Member]
Concentration Risk [Line Items]
Concentration risk, percentage of total	18.00%	15.00%
Accounts Receivable, Net, Less BIEC [Member] \| Credit Concentration Risk [Member] \| Customer with Third Highest Net Accounts Receivable Position [Member]
Concentration Risk [Line Items]
Concentration risk, percentage of total	12.00%
Revenue [Member] \| Customer Concentration Risk [Member] \| Ten Largest Customers [Member]
Concentration Risk [Line Items]
Number of customers			10	10	10	10
Concentration risk, percentage of total			76.00%	84.00%	73.00%	79.00%

Related Party Transactions (Leases and Other Transactions) (Narrative) (Details) $ in Thousands	1 Months Ended	3 Months Ended		5 Months Ended	6 Months Ended		12 Months Ended
	Feb. 28, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($) entity	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Related Party Transaction [Line Items]
Payments of acquisition-related contingent consideration					$ 15,929	$ 6,676
Management [Member] \| 2017 Oil and Gas Acquisition [Member]
Related Party Transaction [Line Items]
Business combinations, cash paid (in dollars)							$ 40,600
Contingent consideration, earn-out liabilities		$ 59,900		$ 59,900	59,900
Payments of acquisition-related contingent consideration		5,700
Management [Member] \| Lease Agreements [Member]
Related Party Transaction [Line Items]
Payments, related party		10,800	$ 14,400		18,300	27,100
Payables, related party		3,000		3,000	3,000		100
Management [Member] \| Service Agreements [Member]
Related Party Transaction [Line Items]
Payments, related party		4,400	$ 7,900		13,300	$ 14,500
Payables, related party		14,200		14,200	$ 14,200		5,200
Management [Member] \| Construction Contracts [Member]
Related Party Transaction [Line Items]
Number of entities \| entity					2
Revenue, related party		3,600			$ 6,300
Receivables, net of BIEC, related parties		300		300	300		$ 200
Immediate Family Member of Management [Member] \| Construction Management Firm Specializing in Steel Building Systems [Member]
Related Party Transaction [Line Items]
Business combinations, cash paid (in dollars)	$ 6,100
Contingent consideration, earn-out liabilities		$ 700		700	$ 700
Business combinations, liabilities assumed, notes payable	$ 2,600
Repayments of notes payable				$ 2,600

Related Party Transactions (CCI) (Narrative) (Details) - CCI [Member] - Immediate Family Member of Management [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Related Party Transaction [Line Items]
Equity investment, ownership percentage	15.00%		15.00%
Equipment [Member]
Related Party Transaction [Line Items]
Payments, related party	$ 5.0	$ 11.0	$ 10.9	$ 12.0
Payables, related party	$ 14.4		$ 14.4

Related Party Transactions (Subcontracting Arrangements and Other Transactions) (Narrative) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) employee	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) employee	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Management [Member] \| Subcontracting Arrangements [Member] \| Related Contractor or Supplier [Member]
Related Party Transaction [Line Items]
Number of additional management employees, subcontracting arrangement \| employee	2		2
Payments or expenses, related party	$ 1.8	$ 15.0	$ 6.8	$ 15.5
Payables, related party	2.3		2.3		$ 2.0
Management [Member] \| Service Agreements [Member]
Related Party Transaction [Line Items]
Payments or expenses, related party	4.4	7.9	13.3	14.5
Payables, related party	14.2		14.2		5.2
Management [Member] \| Lease Agreements [Member]
Related Party Transaction [Line Items]
Payments or expenses, related party	10.8	14.4	18.3	27.1
Payables, related party	3.0		3.0		0.1
Executive Officers [Member] \| Employee Leasing Arrangements [Member] \| Related Customer [Member]
Related Party Transaction [Line Items]
Charges, related party	0.2	0.2	0.4	0.4
Receivables, related party	0.2		0.2		0.2
Executive Officers [Member] \| Service Agreements [Member] \| Related Customer [Member]
Related Party Transaction [Line Items]
Revenue, related parties	0.2	0.2	0.5	0.4
Receivables, related party	0.3		0.3		$ 0.3
Chairman, Board of Directors [Member] \| Lease Agreements [Member] \| Aircraft [Member]
Related Party Transaction [Line Items]
Payments or expenses, related party	$ 0.5	$ 0.5	$ 1.1	$ 1.0

Related Party Transactions (Equity Method Investment) (Narrative) (Details) - 2017 Acquisitions [Member] - Equity Method Investee [Member] - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Equity method investment, ownership percentage	40.00%
Amounts outstanding, net, related party	$ 0.1	$ 0.3

Related Party Transactions (Contractual Joint Venture) (Narrative) (Details) - Joint Venture [Member] - Pacer [Member] $ in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 CAD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2017 CAD ($)	Dec. 31, 2017 USD ($)
Related Party Transaction [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage					35.00%	35.00%
Performance Guarantee [Member]
Related Party Transaction [Line Items]
Guarantees issued, related party					$ 132.1		$ 132.1
Canadian Dollars [Member]
Related Party Transaction [Line Items]
Revenue, related party	$ 0.2	$ 0.2	$ 0.4	$ 0.3
Accounts receivable, net of BIEC, related parties						$ 0.1		$ 0.8
Financing or amounts advanced, related party	$ 1.5	$ 2.3	$ 2.1	$ 3.1
Canadian Dollars [Member] \| Performance Guarantee [Member]
Related Party Transaction [Line Items]
Guarantees issued, related party						$ 100.5		$ 105.1

Related Party Transactions (Non-Controlling Interests) (Narrative) (Details) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended
	Oct. 31, 2017 USD ($) subsidiary	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)
Related Party Transaction [Line Items]
Distributions to non-controlling interests					$ 559	$ 1,280
Payments of acquisition-related contingent consideration					15,929	$ 6,676
Management [Member]
Related Party Transaction [Line Items]
Distributions to non-controlling interests			$ 600	$ 1,300
Payments to acquire remaining non-controlling interests	$ 21,400
Management [Member] \| Acquisition of Non-Controlling Interests [Member]
Related Party Transaction [Line Items]
Number of subsidiaries, non-controlling interests \| subsidiary	1
Contingent consideration, earn-out liabilities		$ 10,000			$ 10,000
Payments of acquisition-related contingent consideration		$ 4,600

Related Party Transactions (Split Dollar Agreements) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Chairman, Board of Directors [Member]
Related Party Transaction [Line Items]
Payments for life insurance policies	$ 0.5	$ 0.5
Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Payments for life insurance policies	0.7	$ 0.7
Executive Officers [Member] \| Other Long-Term Assets [Member]
Related Party Transaction [Line Items]
Life insurance assets, carrying amount	$ 17.9		$ 16.6

Supplemental Guarantor Financial Information (Narrative) (Details)	Jun. 30, 2018
Senior Notes [Member] \| 4.875% Senior Notes [Member]
Condensed Unaudited Consolidating Financial Information [Line Items]
Debt instrument, interest rate (percentage)	4.875%

Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss)) (Details) - USD ($)
$ in Thousands

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]

Costs of revenue, excluding depreciation and amortization

$ 1,617,804

$ 1,890,180

$ 3,014,638

$ 3,048,364

1,366,584

1,626,335

2,603,883

2,597,469

51,676

45,379

101,615

88,282

67,602

70,823

131,224

135,604

20,795

14,791

37,854

27,388

(5,824)

(6,060)

(11,409)

(7,706)

788

146

(2,301)

576

116,183

138,766

153,772

206,751

Net income (loss) before equity in income from subsidiaries

(35,782)

(55,434)

(46,908)

(82,792)

80,400

83,300

106,900

124,000

Equity in income (losses) from subsidiaries, net of tax

Net (loss) income attributable to non-controlling interests

80,401

83,332

106,864

123,959

(91)

1,664

(188)

1,321

^[1]

80,492

81,668

107,052

122,638

Reportable Legal Entities [Member] | MasTec, Inc. [Member]

81,686

81,197

115,342

123,638

Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]

Costs of revenue, excluding depreciation and amortization

800

600

1,500

1,200

(800)

(600)

(1,500)

(1,200)

Net income (loss) before equity in income from subsidiaries

200

400

(600)

(400)

(1,100)

(800)

Equity in income (losses) from subsidiaries, net of tax

81,100

82,100

108,200

123,400

Net (loss) income attributable to non-controlling interests

80,500

81,700

107,100

122,600

80,500

81,700

107,100

122,600

Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]

81,800

79,500

115,500

122,300

Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]

Costs of revenue, excluding depreciation and amortization

1,556,900

1,820,000

2,822,500

2,903,200

1,309,100

1,557,900

2,445,300

2,446,500

46,200

38,200

89,500

73,500

63,100

66,700

122,400

126,400

37,100

30,500

70,000

58,400

1,200

(5,300)

(1,400)

(5,300)

100,200

132,000

96,700

203,700

Net income (loss) before equity in income from subsidiaries

(25,900)

(47,900)

(24,900)

(74,200)

74,300

84,100

71,800

129,500

Equity in income (losses) from subsidiaries, net of tax

Net (loss) income attributable to non-controlling interests

74,300

84,100

71,800

129,500

1,800

1,600

74,300

82,300

71,800

127,900

Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]

74,300

84,100

71,800

129,500

Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]

Costs of revenue, excluding depreciation and amortization

84,000

85,500

269,600

173,400

80,600

83,700

236,100

179,200

5,500

7,200

12,100

14,800

3,700

3,500

7,300

8,000

(16,300)

(15,700)

(32,100)

(31,000)

(5,800)

(6,100)

(11,400)

(7,700)

(400)

5,500

(900)

5,900

16,700

7,400

58,500

4,200

Net income (loss) before equity in income from subsidiaries

(10,100)

(7,700)

(22,300)

(9,000)

6,600

(300)

36,200

(4,800)

Equity in income (losses) from subsidiaries, net of tax

Net (loss) income attributable to non-controlling interests

6,600

(300)

36,200

(4,800)

(100)

(200)

(300)

6,700

(200)

36,400

(4,500)

Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]

8,000

(2,500)

44,700

(5,100)

Eliminations [Member]

Costs of revenue, excluding depreciation and amortization

(23,100)

(15,300)

(77,500)

(28,200)

(23,100)

(15,300)

(77,500)

(28,200)

Net income (loss) before equity in income from subsidiaries

Equity in income (losses) from subsidiaries, net of tax

(81,100)

(82,100)

(108,200)

(123,400)

Net (loss) income attributable to non-controlling interests

(81,100)

(82,100)

(108,200)

(123,400)

(81,100)

(82,100)

(108,200)

(123,400)