MasTec (MTZ) 10-Q 29 Oct 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Oct. 26, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-08106
Entity Registrant Name	MasTec, Inc.
Entity Central Index Key	0000015615
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Incorporation, State or Country Code	FL
Entity Tax Identification Number	65-0829355
Entity Address, Address Line One	800 S. Douglas Road, 12th Floor
Entity Address, City or Town	Coral Gables,
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33134
City Area Code	305
Local Phone Number	599-1800
Title of 12(b) Security	Common Stock, $0.10 Par Value
Trading Symbol	MTZ
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		73,866,947

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 1,698,279	$ 2,016,618	$ 4,684,180	$ 5,473,965
Costs of revenue, excluding depreciation and amortization	1,380,522	1,690,558	3,948,644	4,636,006
Depreciation	71,397	50,515	182,173	160,019
Amortization of intangible assets	11,200	4,681	28,384	14,152
General and administrative expenses	72,690	77,146	243,163	220,581
Interest expense, net	13,553	19,297	45,365	58,178
Equity in earnings of unconsolidated affiliates	(7,445)	(6,966)	(22,092)	(19,778)
Loss on extinguishment of debt	5,569	0	5,569	0
Other (income) expense, net	(6,612)	8,002	(18,481)	16,323
Income before income taxes	157,405	173,385	271,455	388,484
Provision for income taxes	(40,520)	(43,303)	(61,681)	(95,073)
Net income	116,885	130,082	209,774	293,411
Net income attributable to non-controlling interests	394	1,486	48	1,993
Net income attributable to MasTec, Inc.	$ 116,491	$ 128,596	$ 209,726	$ 291,418
Earnings per share (Note 2):
Basic earnings per share (in dollars per share)	$ 1.61	$ 1.71	$ 2.87	$ 3.88
Basic weighted average common shares outstanding	72,138	75,217	72,971	75,131
Diluted earnings per share (in dollars per share)	$ 1.59	$ 1.69	$ 2.84	$ 3.85
Diluted weighted average common shares outstanding	73,095	75,934	73,787	75,760

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 116,885	$ 130,082	$ 209,774	$ 293,411
Other comprehensive (loss) income:
Foreign currency translation losses, net of tax	(616)	(334)	(1,753)	(321)
Unrealized gains (losses) on investment activity, net of tax	2,839	(7,108)	(21,447)	(21,302)
Comprehensive income	119,108	122,640	186,574	271,788
Comprehensive income attributable to non-controlling interests	394	1,486	48	1,993
Comprehensive income attributable to MasTec, Inc.	$ 118,714	$ 121,154	$ 186,526	$ 269,795

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 238,174	$ 71,427
Accounts receivable, net of allowance	917,099	850,326
Contract assets	1,019,879	1,024,568
Inventories, net	85,541	100,069
Prepaid expenses	44,365	52,000
Other current assets	29,017	75,169
Total current assets	2,334,075	2,173,559
Property and equipment, net	994,193	905,835
Operating lease assets	187,531	229,903
Goodwill, net	1,231,717	1,221,440
Other intangible assets, net	191,673	211,528
Other long-term assets	262,560	254,741
Total assets	5,201,749	4,997,006
Current liabilities:
Current portion of long-term debt, including finance leases	138,935	118,429
Current portion of operating lease liabilities	74,439	81,561
Accounts payable	582,849	535,029
Accrued salaries and wages	108,796	87,562
Other accrued expenses	169,748	115,581
Contract liabilities	368,184	206,180
Other current liabilities	71,203	74,784
Total current liabilities	1,514,154	1,219,126
Long-term debt, including finance leases	1,164,457	1,314,030
Long-term operating lease liabilities	125,639	154,553
Deferred income taxes	301,216	296,326
Other long-term liabilities	219,138	221,280
Total liabilities	3,324,604	3,205,315
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 - 92,761,041 and 91,909,430 (including 1,732,454 and 1,221,593 of unvested stock awards) as of September 30, 2020 and December 31, 2019, respectively	9,276	9,191
Capital surplus	829,495	809,753
Retained earnings	1,720,435	1,510,709
Accumulated other comprehensive loss	(98,906)	(75,706)
Treasury stock, at cost: 18,941,926 shares and 15,344,917 shares as of September 30, 2020 and December 31, 2019, respectively	(586,955)	(466,727)
Total MasTec, Inc. shareholders’ equity	1,873,345	1,787,220
Non-controlling interests	3,800	4,471
Total equity	1,877,145	1,791,691
Total liabilities and equity	$ 5,201,749	$ 4,997,006
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	92,761,041	91,909,430
Treasury stock, shares	18,941,926	15,344,917
Common Stock [Member]
Equity
Total equity	$ 9,276	$ 9,191
Common stock, shares issued	92,761,041	91,909,430
Restricted Stock Awards [Member] | Common Stock [Member]
Unvested stock awards (in shares)	1,732,454	1,221,593

Consolidated Statements of Equi

Consolidated Statements of Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Total MasTec, Inc. Shareholders' Equity [Member]	Non-Controlling Interests [Member]
Beginning balance, common shares outstanding (in shares) at Dec. 31, 2018		91,327,009
Beginning balance at Dec. 31, 2018	$ 1,392,024	$ 9,133	$ (466,125)	$ 789,009	$ 1,118,375	$ (60,494)	$ 1,389,898	$ 2,126
Beginning balance, treasury shares (in shares) at Dec. 31, 2018			(15,329,817)
Condensed Unaudited Consolidated Statements of Equity
Net income	293,411				291,418		291,418	1,993
Other comprehensive income (loss)	(21,623)					(21,623)	(21,623)
Non-cash stock-based compensation	12,132			12,132			12,132
Issuance of restricted shares, net (in shares)		232,499
Issuance of restricted shares, net	0	$ 23		(23)			0
Other stock issuances, net of shares withheld for taxes (in shares)		94,650
Other stock issuances, net of shares withheld for taxes	3,378	$ 9		3,369			3,378
Acquisition of treasury stock, at cost (in shares)			(15,100)
Acquisition of treasury stock, at cost	(602)		$ (602)				(602)
Contributions from noncontrolling interests	584						0	584
Ending balance, common shares outstanding (in shares) at Sep. 30, 2019		91,654,158
Ending balance at Sep. 30, 2019	1,679,304	$ 9,165	$ (466,727)	804,487	1,409,793	(82,117)	1,674,601	4,703
Ending balance, treasury shares (in shares) at Sep. 30, 2019			(15,344,917)
Beginning balance, common shares outstanding (in shares) at Jun. 30, 2019		91,626,986
Beginning balance at Jun. 30, 2019	1,551,338	$ 9,163	$ (466,727)	799,162	1,281,198	(74,675)	1,548,121	3,217
Beginning balance, treasury shares (in shares) at Jun. 30, 2019			(15,344,917)
Condensed Unaudited Consolidated Statements of Equity
Net income	130,082				128,596		128,596	1,486
Other comprehensive income (loss)	(7,442)					(7,442)	(7,442)
Non-cash stock-based compensation	4,192			4,192			4,192
Issuance of restricted shares, net (in shares)		(920)
Issuance of restricted shares, net	0	$ 0		0			0
Other stock issuances, net of shares withheld for taxes (in shares)		28,092
Other stock issuances, net of shares withheld for taxes	1,135	$ 2		1,133			1,135
Ending balance, common shares outstanding (in shares) at Sep. 30, 2019		91,654,158
Ending balance at Sep. 30, 2019	$ 1,679,304	$ 9,165	$ (466,727)	804,487	1,409,793	(82,117)	1,674,601	4,703
Ending balance, treasury shares (in shares) at Sep. 30, 2019			(15,344,917)
Beginning balance, common shares outstanding (in shares) at Dec. 31, 2019	91,909,430	91,909,430
Beginning balance at Dec. 31, 2019	$ 1,791,691	$ 9,191	$ (466,727)	809,753	1,510,709	(75,706)	1,787,220	4,471
Beginning balance, treasury shares (in shares) at Dec. 31, 2019	(15,344,917)		(15,344,917)
Condensed Unaudited Consolidated Statements of Equity
Net income	$ 209,774				209,726		209,726	48
Other comprehensive income (loss)	(23,200)					(23,200)	(23,200)
Non-cash stock-based compensation	15,538			15,538			15,538
Issuance of restricted shares, net (in shares)		694,746
Issuance of restricted shares, net	0	$ 69		(69)			0
Other stock issuances, net of shares withheld for taxes (in shares)		156,865
Other stock issuances, net of shares withheld for taxes	$ 4,289	$ 16		4,273			4,289
Acquisition of treasury stock, at cost (in shares)	(3,600,000)		(3,597,009)
Acquisition of treasury stock, at cost	$ (120,228)		$ (120,228)				(120,228)
Distributions to noncontrolling interests	$ (719)						0	(719)
Ending balance, common shares outstanding (in shares) at Sep. 30, 2020	92,761,041	92,761,041
Ending balance at Sep. 30, 2020	$ 1,877,145	$ 9,276	$ (586,955)	829,495	1,720,435	(98,906)	1,873,345	3,800
Ending balance, treasury shares (in shares) at Sep. 30, 2020	(18,941,926)		(18,941,926)
Beginning balance, common shares outstanding (in shares) at Jun. 30, 2020		92,665,097
Beginning balance at Jun. 30, 2020	$ 1,750,836	$ 9,267	$ (586,955)	821,584	1,603,944	(101,129)	1,746,711	4,125
Beginning balance, treasury shares (in shares) at Jun. 30, 2020			(18,941,926)
Condensed Unaudited Consolidated Statements of Equity
Net income	116,885				116,491		116,491	394
Other comprehensive income (loss)	2,223					2,223	2,223
Non-cash stock-based compensation	5,639			5,639			5,639
Issuance of restricted shares, net (in shares)		1,391
Issuance of restricted shares, net	0	$ 0		0			0
Other stock issuances, net of shares withheld for taxes (in shares)		94,553
Other stock issuances, net of shares withheld for taxes	2,281	$ 9		2,272			2,281
Distributions to noncontrolling interests	$ (719)						0	(719)
Ending balance, common shares outstanding (in shares) at Sep. 30, 2020	92,761,041	92,761,041
Ending balance at Sep. 30, 2020	$ 1,877,145	$ 9,276	$ (586,955)	$ 829,495	$ 1,720,435	$ (98,906)	$ 1,873,345	$ 3,800
Ending balance, treasury shares (in shares) at Sep. 30, 2020	(18,941,926)		(18,941,926)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 116,885	$ 130,082	$ 209,774	$ 293,411
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	71,397	50,515	182,173	160,019
Amortization of intangible assets	11,200	4,681	28,384	14,152
Non-cash interest expense, net			2,201	1,691
Non-cash stock-based compensation expense			15,538	12,132
Provision for deferred income taxes			7,947	8,546
Provision for credit losses	1,900	400	14,213	1,326
Equity in earnings of unconsolidated affiliates	(7,445)	(6,966)	(22,092)	(19,778)
Gains on sales of assets, net			(12,874)	(9,627)
Other non-cash items, net			8,833	(2,841)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable, net of allowance			(49,802)	(33,522)
Contract assets			10,637	34,253
Inventories			15,645	21,293
Other assets, current and long-term portion			38,729	16,641
Accounts payable and accrued expenses			109,689	(30,641)
Contract liabilities			160,648	(52,537)
Other liabilities, current and long-term portion			(7,185)	26,876
Net cash provided by operating activities			712,458	441,394
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired			(11,251)	(94,647)
Capital expenditures			(183,725)	(85,095)
Proceeds from sale of property and equipment			29,744	27,102
Payments for other investments			(17,436)	(5,589)
Proceeds from other investments			648	14,705
Other investing activities, net			4,843	0
Net cash used in investing activities			(177,177)	(143,524)
Cash flows from financing activities:
Proceeds from credit facilities			1,415,426	2,185,714
Repayments of credit facilities			(1,725,845)	(2,371,965)
Proceeds from issuance of 4.50% senior notes			600,000	0
Repayments of 4.875% senior notes			(400,000)	0
Repayments of other borrowings, net			(50)	(333)
Payments of finance lease obligations			(92,260)	(59,045)
Payments of acquisition-related contingent consideration			39,379	29,267
(Distributions to) proceeds from non-controlling interests			(719)	584
Proceeds from stock-based awards			5,483	3,414
Payments for stock-based awards			(614)	(34)
Repurchases of common stock			(120,228)	(5,652)
Other financing activities, net			(11,078)	(5,459)
Net cash used in financing activities			(369,264)	(282,043)
Effect of currency translation on cash			730	(154)
Net increase in cash and cash equivalents			166,747	15,673
Cash and cash equivalents - beginning of period			71,427	27,422	$ 27,422
Cash and cash equivalents - end of period	$ 238,174	$ 43,095	238,174	43,095	$ 71,427
Supplemental cash flow information:
Interest paid			57,098	73,570
Income tax payments, net of refunds			12,091	73,502
Supplemental disclosure of non-cash information:
Additions to property and equipment from finance leases			$ 86,083	$ 163,458
4.50% Senior Notes [Member] | Senior Notes [Member]
Debt instrument, interest rate (percentage)	4.50%		4.50%
4.875% Senior Notes [Member] | Senior Notes [Member]
Debt instrument, interest rate (percentage)	4.875%		4.875%

Business, Basis of Presentation

Business, Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
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, utility and other infrastructure, such as: wireless, wireline/fiber and customer fulfillment activities; pipeline infrastructure; electrical utility transmission and distribution; power generation, including from clean energy and renewable sources; 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) Clean Energy and Infrastructure; and (5) Other. During the second quarter of 2020, the Company renamed its Power Generation and Industrial segment as the Clean Energy and Infrastructure segment to better represent the nature of the segment’s operations, end markets and customer characteristics. There was no change to the composition of the segment or its historical results. Basis of Presentation The accompanying consolidated financial statements are unaudited and 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 consolidated balance sheet as of December 31, 2019 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 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, 2019 contained in the Company’s 2019 Annual Report on Form 10-K (the “2019 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. When necessary, 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 consolidated financial statements are adequate to make the information not misleading. Principles of Consolidation The accompanying 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, except for mandatorily redeemable non-controlling interests, which are recorded within liabilities. 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 over which it has the ability to exert significant influence, are accounted for using the equity method of accounting. For equity investees in which the Company has an undivided interest in the assets, liabilities and profits or losses of an unincorporated entity, but does not exercise control over the entity, the Company consolidates its proportional interest in the accounts of the entity. 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 included 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 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, including the potential future effects of the COVID-19 pandemic and other relevant global events. These estimates form the basis for making judgments about the Company’s operating results and the carrying values of assets and liabilities that are not readily apparent from other sources. 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. 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 and probability of variable consideration included in the contract transaction price; fair value estimates, including those related to acquisitions, valuations of goodwill and intangible assets, acquisition-related contingent consideration and other liabilities, equity investments and other long-lived assets; allowances for credit losses; 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. COVID-19 Pandemic During March 2020, the World Health Organization declared a global pandemic related to the rapidly growing outbreak of a novel strain of coronavirus (“COVID-19”). The COVID-19 pandemic has significantly affected economic conditions in the United States and internationally, as national, state and local governments reacted to the public health crisis by requiring mitigation measures resulting in workforce, supply chain and other market disruptions that have created significant uncertainties in the U.S. and global economies and disrupted business activities for an uncertain period of time. Although certain jurisdictions have subsequently taken steps to lift or ease such restrictions to various degrees, such lifting or easing could subsequently be reversed, or new restrictions imposed, due to a rise in cases of COVID-19. Most of the Company’s construction services have been and currently are deemed essential under state and local pandemic mitigation orders, and all of its business segments continue to operate. Where safe and possible, the Company has generally been directed by its customers to maintain normal work schedules. Management’s top priority has been to take appropriate actions to protect the health and safety of its employees, customers and business partners, including adjusting its standard operating procedures to respond to evolving health guidelines. The COVID-19 pandemic has had a negative impact on the Company’s operations and is expected to have some continued negative impact. These impacts include lost productivity from governmental permitting approval delays, reduced crew productivity due to social distancing, other mitigation measures or other factors, the health and availability of work crews or other key personnel, including subcontractors or supply chain disruptions, and/or delayed project start dates or project shutdowns or cancellations that may be mandated or requested by governmental authorities or others, all of which could result in lower revenue or higher operating costs and/or create lower levels of overhead cost absorption. In response to the COVID-19 pandemic, the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was signed into law on March 27, 2020. The CARES Act provides for various tax relief and incentive measures, including provisions permitting the deferral and/or reduction of certain federal and payroll tax amounts. The Company has pursued certain of these relief provisions, and for the nine month period ended September 30, 2020, has deferred approximately $22 million of payroll taxes, net. The Company will continue to evaluate the potential effects of the CARES Act on its financial position, results of operations and cash flows. Management believes that it is taking appropriate steps to mitigate any potential impact to the Company; however, given the uncertainty regarding the potential effects of the COVID-19 pandemic, any future impacts cannot be quantified or predicted with specificity. Significant Accounting Policies Revenue Recognition The Company recognizes revenue from contracts with customers under Accounting Standards Codification (“ASC”) Topic 606 (“Topic 606”). 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. Revenue is primarily recognized by the Company over time utilizing the cost-to-cost measure of progress, which best depicts the continuous transfer of control of goods or services to the customer, and correspondingly, when performance obligations are satisfied for the related contracts. Contracts. The Company derives revenue primarily from construction projects performed under: (i) 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 either a time and materials, or a fixed price per unit basis; and (ii) 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 projects performed under master service and other service agreements totaled 32% of consolidated revenue for both the three month periods ended September 30, 2020 and 2019, and totaled 36% and 35% for the nine month periods ended September 30, 2020 and 2019, respectively. For certain master service and other service agreements under which the Company 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 4% of consolidated revenue for both the three month periods ended September 30, 2020 and 2019, and accounted for approximately 5% for both the nine month periods ended September 30, 2020 and 2019. Substantially all of the Company’s other revenue is recognized over time. The total contract transaction price and cost estimation processes used 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 the Company’s 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 nine month periods ended September 30, 2020 and 2019, 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, 2019 and 2018. Revenue recognized for the three month periods ended September 30, 2020 and 2019 as a result of changes in total contract transaction price estimates, including for variable consideration, from performance obligations satisfied or partially satisfied in prior periods, totaled approximately $8.8 million and $13.3 million, respectively, and totaled $11.5 million and $52.2 million for the nine month periods ended September 30, 2020 and 2019, respectively. The Company may incur certain costs that can be capitalized, such as initial set-up or mobilization costs. Such costs, which are amortized over the life of the respective projects, were not material as of September 30, 2020 or December 31, 2019. 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 vast majority of the Company’s performance obligations are completed within one year. Remaining performance obligations represent the amount of unearned transaction prices under contracts for which work is wholly or partially unperformed, including the Company’s share of unearned transaction prices from its proportionately consolidated non-controlled joint ventures. As of September 30, 2020, the amount of the Company’s remaining performance obligations was $5.3 billion. Based on current expectations, the Company expects to recognize approximately $1.6 billion of its remaining performance obligations as revenue during 2020, with the remainder to be recognized primarily in 2021. Variable Consideration. Transaction prices for the Company’s contracts may include variable consideration, which comprises items such as change orders, claims and incentives. Management estimates variable consideration for a performance obligation utilizing estimation methods that it believes best predict the amount of consideration to which the Company will be entitled. Management’s estimates of variable consideration and the determination of whether to include estimated amounts in transaction prices 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 at the time of the estimate. To the extent unapproved change orders, claims and other variable consideration reflected in transaction prices are not resolved in the Company’s favor, or to the extent incentives reflected in transaction prices are not earned, there could be reductions in, or reversals of, previously recognized revenue. As of September 30, 2020 and December 31, 2019, the Company included approximately $50 million and $27 million, respectively, of change orders and/or claims in transaction prices for certain contracts that were in the process of being resolved in the ordinary course of business, including through negotiation, arbitration and other proceedings. These transaction price adjustments, when earned, are included within contract assets or accounts receivable, net of allowance, as appropriate. As of both September 30, 2020 and December 31, 2019, these change orders and/or claims were primarily related to certain projects in the Company’s Oil and Gas and Electrical Transmission segments. 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 agreement by customers could be higher or lower than such estimated amounts. Recently Issued Accounting Pronouncements See 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 2019 Form 10-K. Accounting Pronouncements Adopted in 2020 In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40) Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (“ASU 2018-15”) to reduce diversity in practice in accounting for the costs of implementing cloud computing arrangements that are service contracts. ASU 2018-15 aligns the requirements for capitalizing implementation costs incurred in a cloud computing arrangement that is a service contract with the requirements for internal-use software. Accounting for the service element of the cloud computing arrangement is not affected by the new guidance. Under ASU 2018-15, amortization expense, payments for and asset balances related to such capitalized implementation costs are to be presented within the same line items of the entity’s statements of operations, cash flows and balance sheets, respectively, as the related service fee activity and balances would be presented. ASU 2018-15, which the Company adopted on a prospective basis during the first quarter of 2020, did not have a material effect on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) Disclosure Framework - Changes to the Disclosure Requiremen ts for Fair Value Measurement (“ASU 2018-13”). ASU 2018-13, which is intended to improve the effectiveness of fair value measurement disclosures, modifies the disclosure requirements for certain estimates and assumptions used in determining the fair value of assets and liabilities. ASU 2018-13, which the Company adopted during the first quarter of 2020, did not have a material effect on the Company’s consolidated financial statements. See Note 4 - Fair Value of Financial Instruments for disclosure updates pertaining to significant unobservable inputs used to develop fair value estimates for certain of the Company’s Level 3 financial instruments. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments . This ASU, together with its related clarifying ASUs (collectively, “ASU 2016-13”), introduced an expected credit loss methodology for the measurement and recognition of credit losses on most financial assets, including financial assets arising from revenue transactions, such as accounts receivable and contract assets. The new expected credit loss methodology, which is based on historical experience, current conditions and reasonable and supportable forecasts, replaced the incurred loss model for measuring and recognizing expected credit losses. The Company adopted this ASU in the first quarter of 2020 and incorporated this guidance into its methodology for estimating its accounts receivable allowances. Based on historical trends, the financial condition of the Company’s customers and management’s expectations of economic and industry factors affecting the Company’s customers, ASU 2016-13 did not have a material effect on the Company’s consolidated financial statements upon adoption. Future credit loss expectations could be affected by changes in estimates or developing trends, including from changes in credit quality of the Company’s customers, changes in specific risks associated with the Company’s financial assets, or from changes in management’s expectations of future economic and industry conditions or other factors. Management actively monitors the economic environment, including any potential effects from the COVID-19 pandemic and/or volatility in the oil and gas markets on the credit quality of the Company’s customers and/or its financial assets. For additional information about the Company’s accounts receivable and related allowances, see Note 5 - Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Note 2 – Earnings Per Share Basic earnings or loss per share is computed by dividing net income 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 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 September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 Net income attributable to MasTec: Net income - basic and diluted (a) $ 116,491 $ 128,596 $ 209,726 $ 291,418 Weighted average shares outstanding: Weighted average shares outstanding - basic 72,138 75,217 72,971 75,131 Dilutive common stock equivalents (b) 957 717 816 629 Weighted average shares outstanding - diluted 73,095 75,934 73,787 75,760 (a) Calculated as total net income less amounts attributable to non-controlling interests. (b) For the nine month period ended September 30, 2020, there were 58,759 anti-dilutive common stock equivalents. The Company repurchased approximately 3.6 million shares of its common stock during the nine month period ended September 30, 2020, as discussed in Note 11 - Equity. The effect of these repurchases on the Company’s weighted average shares outstanding for the nine month period ended September 30, 2020 was a reduction of approximately 2.6 million shares, due to the timing of the repurchases.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Note 3 – Goodwill and Other Intangible Assets The following table provides balances for goodwill by reportable segment as of September 30, 2020 (in millions): Communications Oil and Gas Electrical Clean Energy and Infrastructure Total Goodwill Goodwill, gross $ 551.4 $ 496.0 $ 150.1 $ 152.8 $ 1,350.3 Accumulated impairment loss — (118.6) — — (118.6) Goodwill, net $ 551.4 $ 377.4 $ 150.1 $ 152.8 $ 1,231.7 For the nine month period ended September 30, 2020, goodwill included additions of $5.2 million from new business combinations and a net increase of $5.4 million from measurement period adjustments. Currency translation effects related to goodwill and accumulated impairment losses for the nine month period ended September 30, 2020 totaled approximately $3.2 million of losses and $2.9 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 Pre-Qualifications Other (a) Total Other intangible assets, gross, as of December 31, 2019 $ 34.5 $ 72.9 $ 286.5 $ — $ 26.3 $ 420.2 Accumulated amortization (191.2) — (17.5) (208.7) Other intangible assets, net, as of December 31, 2019 $ 34.5 $ 72.9 $ 95.3 $ — $ 8.8 $ 211.5 Additions from new business combinations — — 9.7 — 0.1 9.8 Classification changes (b) — (69.8) — 69.8 — — Measurement period adjustments (c) — — (0.2) — — (0.2) Currency translation adjustments — (3.1) — 2.1 — (1.0) Amortization expense (19.8) (7.1) (1.5) (28.4) Other intangible assets, net, as of September 30, 2020 $ 34.5 $ — $ 85.0 $ 64.8 $ 7.4 $ 191.7 (a) Consists principally of trade names and non-compete agreements. (b) In connection with its first quarter assessment of goodwill and indefinite-lived intangible assets, management reassessed the indefinite-life classification of its two pre-qualification intangible assets. Management determined that, based on changes in the assets’ characteristics, including current and expected changes in the customer mix of the associated reporting units, a finite-life classification for these assets was more appropriate. As a result, in the first quarter of 2020, the Company changed the classification of these pre-qualification intangible assets from indefinite-lived to finite-lived and began amortizing them on an accelerated basis, with an estimated remaining weighted average useful life of approximately 12 years. (c) Represents adjustments to preliminary estimates of fair value within the measurement period of up to one year from the date of acquisition. Quarterly Assessment for Indicators of Impairment. During the third quarter of 2020, in conjunction with the Company’s quarterly review for indicators of impairment, management performed quantitative assessments of the goodwill associated with three reporting units within the Oil and Gas segment. Based on the results of these assessments, management determined that the estimated fair value of one of the reporting units, for which the related goodwill had a carrying value of approximately $15.3 million, exceeded its carrying value by approximately 10%, and the estimated fair values of the other two reporting units were determined to substantially exceed their carrying values. Significant changes in the assumptions or estimates used in management’s assessment, such as a reduction in profitability and/or cash flows, could result in non-cash goodwill and indefinite-lived intangible asset impairment charges in the future. 2020 Acquisitions. For the nine month period ended September 30, 2020, MasTec completed four acquisitions. Through a 96%-owned consolidated subsidiary, the Company acquired all of the equity interests in a heavy civil infrastructure construction company that is included within the Company’s Clean Energy and Infrastructure segment. The Company also acquired all of the equity interests in a utility service and telecommunications construction contractor that is included within the Company’s Communications segment . In addition, the Company acquired the assets of two entities, one that sp ecializes in wireless telecommunications and one that specializes in electrical transmission services. The aggregate purchase price for these entities was composed of approximately $9.8 million in cash, net of cash acquired, with an additional $2.8 million due through 2023, subject to certain indemnification provisions, and a five -year earn-out liability valued at approximately $7.2 million . E arn-outs are generally payable annually and are recorded within other current and other long-term liabilities in the consolidated balance sheets. As of September 30, 2020, the range of remaining potential undiscounted earn-out liabilities for the 2020 acquisitions was estimated to be up to $13 million; however, there is no maximum payment amount. Determination of the estimated fair values of the net assets acquired and the estimated earn-out liabilities for these acquisitions was preliminary as of September 30, 2020; as a result, further adjustments to these estimates may occur. 2019 Acquisitions. During 2019, MasTec completed six acquisitions, one of which specializes in water infrastructure for pipeline companies and is included within the Company’s Oil and Gas segment, four o f which are included within the Company’s Communications segment, including a wireline/fiber deployment construction contractor and a telecommunications company specializing in a broad range of end-to-end wireless telecommunications solutions, and one of which specializes in construction projects in the power industry and is included in the Company’s Clean Energy and Infrastructure segment . For all but one of these acquisitions, the Company acquired all of the equity interests in the related entities. For the telecommunications company specializing in wireless telecommunications solutions, the Company acquired 96% of the entity’s equity interests, with the obligation to acquire the balance over time. The aggregate purchase price for these entities, as adjusted, was composed of approximately $176.6 million in cash, net of cash acquired, plus earn-out liabilities and a mandatorily redeemable non-controlling interest valued at approximately $22.3 million and $17.8 million , respectively. The Company refers to its traditional earn-out arrangements and the mandatorily redeemable non-controlling interest collectively as “Earn-outs.” Earn-outs for the 2019 acquisitions have terms ranging from three to five years. As of September 30, 2020, the range of remaining potential undiscounted Earn-out liabilities for the 2019 acquisitions was estimated to be between $2 million and $62 million; however, there is no maximum payment amount. 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 September 30, 2020; as a result, further adjustments to these estimates may occur. Pro Forma Financial Information and Acquisition Results. For the three month periods ended September 30, 2020 and 2019, unaudited supplemental pro forma revenue totaled approximately $1.7 billion and $2.1 billion, respectively, and unaudited supplemental pro forma net income totaled approximately $117.9 million and $127.4 million, respectively. For the nine month periods ended September 30, 2020 and 2019, unaudited supplemental pro forma revenue totaled approximately $4.7 billion and $5.8 billion, respectively, and unaudited supplemental pro forma net income totaled approximately $212.7 million and $300.7 million, respectively. For the three and nine month periods ended September 30, 2020, the Company’s consolidated results of operations included acquisition-related revenue of approximately $69.3 million and $182.4 million, respectively, and included acquisition-related net losses of approximately $4.3 million and $5.0 million, respectively, based on the Company’s consolidated effective tax rates. For the three and nine month periods ended September 30, 2019, the Company’s consolidated results of operations included acquisition-related revenue of approximately $41.7 million and $116.9 million, respectively, and included acquisition-related net income of approximately $1.5 million and acquisition-related net losses of approximately $5.9 million, respectively, based on the Company’s consolidated effective tax rates. 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 Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2020
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, cash collateral deposited with insurance carriers, life insurance assets, equity investments, certain other investments, deferred compensation plan assets and liabilities, accounts payable and other current liabilities, acquisition-related contingent consideration, mandatorily redeemable non-controlling interests 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. Acquisition-Related Contingent Consideration and Other Liabilities Acquisition-related contingent consideration and other liabilities is composed of Earn-outs, which represent the estimated fair value of future amounts payable for businesses that are contingent upon the acquired business achieving certain levels of earnings in the future. As of September 30, 2020 and December 31, 2019, the estimated fair value of the Company’s Earn-out liabilities totaled $132.8 million and $173.2 million, respectively, of which $47.6 million and $54.1 million, respectively, was included within other current liabilities. The fair values of the Company’s Earn-out liabilities are estimated using income approaches such as discounted cash flows or option pricing models, both of which incorporate significant inputs not observable in the market (Level 3 inputs), including management’s estimates and entity-specific assumptions, and are evaluated on an ongoing basis. Key assumptions include the discount rate, which, as of September 30, 2020, ranged from 12.0% to 23.0%, with a weighted average rate of 14.0% based on the relative fair value of each instrument, and probability-weighted projections of earnings before interest, taxes, depreciation and amortization (“EBITDA”). Significant changes in any of these assumptions could result in significantly higher or lower potential Earn-out liabilities. The ultimate payment amounts for the Company’s Earn-out liabilities will be determined based on the actual results achieved by the acquired businesses. As of September 30, 2020, the range of potential undiscounted Earn-out liabilities was estimated to be between $34 million and $199 million; however, there is no maximum payment amount. Earn-out activity consists primarily of additions from new business combinations; changes in the expected fair value of future payment obligations; and payments. Measurement period adjustments for Earn-out liabilities, which are fair value adjustments relating to new information obtained about the facts and circumstances existing as of the date of acquisition for a period of up to one year, are recorded to goodwill. Other revisions to the expected fair values of the Company’s traditional earn-out liabilities are reflected as other income or expense, and for the mandatorily redeemable non-controlling interest, are recorded as interest expense or income. Earn-out payments, to the extent they relate to estimated liabilities as of the date of acquisition, are reflected within financing activities in the consolidated statements of cash flows. Payments in excess of acquisition date liabilities are classified within operating activities. There were no additions to acquisition-related contingent consideration and other liabilities from new business combinations in either of the three month periods ended September 30, 2020 or 2019, and for the nine month periods ended September 30, 2020 and 2019, additions totaled $7.2 million and $16.2 million, respectively. There were no measurement period adjustments for the three month period ended September 30, 2020, and measurement period adjustments for the nine month period ended September 30, 2020 totaled an increase of approximately $1.1 million, and related to a business in the Company’s Communications segment. There were no measurement period adjustments for the three or nine month periods ended September 30, 2019. There were no fair value adjustments for the three month period ended September 30, 2020, and fair value adjustments for the nine month period ended September 30, 2020 totaled a net increase of approximately $1.7 million, and related to businesses in the Company’s Oil and Gas and Communications segments. For the three and nine month periods ended September 30, 2019, fair value adjustments totaled a net increase of approximately $11.2 million and $47.6 million, respectively, and related primarily to businesses in the Company’s Oil and Gas and Communications segments. There were no Earn-out payments in either of the three month periods ended September 30, 2020 or 2019, and for the nine month periods ended September 30, 2020 and 2019, Earn-out payments totaled $50.4 million and $30.0 million, respectively. Equity Investments The Company’s equity investments as of September 30, 2020 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 50% equity interests in each of FM Technology Holdings, LLC, FM USA Holdings, LLC and All Communications Solutions Holdings, LLC, collectively, “FM Tech,” for which the Company’s aggregate investment totals approximately $16 million, and is accounted for as an equity method investment; (iv) the Company’s equity interests in American Virtual Cloud Technologies, Inc., or “AVCT” (formerly named Pensare Acquisition Corp. (“Pensare”)); (v) the Company’s interests in certain proportionately consolidated non-controlled contractual joint ventures; and (vi) certain other equity investments. Investment Arrangements . From time to time, the Company may participate in selected investment or strategic arrangements, including equity interests in various business entities and participation in contractual joint ventures. The Company’s investment and strategic arrangements may involve the extension of loans or other types of financing arrangements, including approximately $6 million of financing commitments as of September 30, 2020. The Company has determined that certain of its investment arrangements are variable interest entities (“VIEs”). As of September 30, 2020, except for one individually insignificant VIE, the Company does not have the power to direct the primary activities that most significantly impact the economic performance of its VIEs nor is it the primary beneficiary. Accordingly, except for the previously mentioned VIE, the Company’s VIEs are not consolidated. Equity investments, other than those accounted for as equity method investments or those that are proportionately 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, if any, less impairment (“adjusted cost basis”). As of September 30, 2020 and December 31, 2019, the aggregate carrying value of the Company’s equity investments, including equity investments measured on an adjusted cost basis, totaled approximately $205 million and $196 million, respectively. As of September 30, 2020 and December 31, 2019, equity investments measured on an adjusted cost basis, including the Company’s investment in CCI, totaled approximately $17 million and $18 million, respectively. There were no material changes in the fair values of, or impairments related to, these investments during either of the nine month periods ended September 30, 2020 or 2019. The Waha JVs. The Waha JVs own and operate certain pipeline infrastructure that transports natural gas to the Mexican border for export. 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 $7.7 million and $6.9 million for the three month periods ended September 30, 2020 and 2019, respectively, and totaled $22.9 million and $19.8 million for the nine month periods ended September 30, 2020 and 2019, respectively. Cumulative undistributed earnings from the Waha JVs, which represents cumulative equity in earnings for the Waha JVs less distributions of earnings, totaled $60.7 million as of September 30, 2020. Distributions of earnings from the Waha JVs, which are included within operating cash flows, totaled $2.4 million and $1.5 million for the three month periods ended September 30, 2020 and 2019, respectively, and totaled $10.2 million and $7.5 million for the nine month periods ended September 30, 2020 and 2019, respectively. 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 $165 million and $174 million as of September 30, 2020 and December 31, 2019, respectively. The Waha JVs 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 their 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 nine month periods ended September 30, 2020, the Company’s proportionate share of unrecognized unrealized activity on these interest rate swaps totaled gains of approximately $2.5 million and losses of approximately $29.5 million, respectively, or gains of $1.9 million and losses of $22.4 million, net of tax, respectively. For the three and nine month periods ended September 30, 2019, the Company’s proportionate share of unrecognized unrealized activity on these interest rate swaps totaled losses of approximately $9.4 million and $28.2 million, respectively, or $7.1 million and $21.3 million, net of tax, respectively. Other Investments. The Company has investments in AVCT. These investments include (i) shares of AVCT common stock, which are equity securities, (ii) warrants for the purchase of AVCT common stock, which are derivative financial instruments, and (iii) debentures that are convertible into shares of AVCT common stock, which are available-for-sale securities. As of September 30, 2020 and December 31, 2019, the Company’s ownership interest in AVCT’s common stock, represented by the AVCT shares, totaled approximately 9% and 21%, respectively, and its aggregate ownership interest, assuming the exercise and conversion of all legally exercisable warrants and convertible debt into AVCT common stock, totaled approximately 22% and 21%, respectively. José R. Mas, MasTec’s Chief Executive Officer, was a director of Pensare through the end of March 2020. The Company paid an aggregate of approximately $5 million for its investments in AVCT, all of which are included within other long-term assets in the Company’s consolidated financial statements. The issued shares and those underlying the derivative instruments are salable at various times subject to various contractual and securities law restrictions. The Company does not have the ability to exert significant influence over the operating and financial policies of AVCT. As of September 30, 2020, the aggregate fair value of the Company’s investments in AVCT approximated $11 million. For the three and nine month periods ended September 30, 2020, the Company recorded unrealized fair value measurement gains, net, on the AVCT securities within other income totaling approximately $0.9 million and $4.7 million, respectively, primarily related to the AVCT shares, for which the fair value was determined based on the market price of identical securities, adjusted for the restrictions on sale, which is a Level 3 input. Unrealized fair value measurement gains on the AVCT convertible debentures recognized within other comprehensive income, as determined based on Monte Carlo simulations, which is a Level 3 input, totaled approximately $0.9 million for both the three and nine month periods ended September 30, 2020. As of December 31, 2019, the AVCT shares were measured on an adjusted cost basis as their fair value was not readily determinable. The aggregate carrying value of the Company’s investment in AVCT as of December 31, 2019, including the AVCT shares and initial warrants, was approximately $2 million. The Company has equity interests in certain telecommunications entities, including FM Tech, that provide services to MasTec. For the three and nine month periods ended September 30, 2020, expense recognized in connection with these arrangements totaled $2.7 million and $9.0 million, respectively, and related amounts payable totaled $0.4 million as of September 30, 2020. Senior Notes As of September 30, 2020, the gross carrying amount of the Company’s 4.50% senior notes due August 15, 2028 (the “4.50% Senior Notes”) totaled $600 million and their estimated fair value totaled $606.0 million. As of December 31, 2019, the gross carrying amount of the Company’s 4.875% senior notes due March 15, 2023 (the “4.875% Senior Notes”) totaled $400 million and their estimated fair value totaled $404.5 million. The estimated fair values of the Company’s senior notes were determined using an “exit price” approach based on Level 1 inputs. See Note

Accounts Receivable, Net of All

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities	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): September 30, December 31, Contract billings $ 939.6 $ 860.4 Less allowance (22.5) (10.1) Accounts receivable, net of allowance $ 917.1 $ 850.3 Retainage 313.1 345.2 Unbilled receivables 706.8 679.4 Contract assets $ 1,019.9 $ 1,024.6 Contract billings represent the amount of performance obligations that have been billed but have not yet been collected, whereas contract assets consist of unbilled receivables and retainage. Unbilled receivables represent 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). For the three and nine month periods ended September 30, 2020, provisions for credit losses totaled $1.9 million and $14.2 million, respectively, including potential credit losses resulting from current economic uncertainty. For the three and nine month periods ended September 30, 2019, provisions for credit losses totaled $0.4 million and $1.3 million, respectively. Impairment losses on contract assets were not material in either period. Contract liabilities consist primarily of deferred revenue. Under certain contracts, the Company may be entitled to invoice the customer and receive payments 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 deferred revenue. Contract liabilities also include the amount of any accrued project losses. Total contract liabilities, including accrued project losses, totaled approximately $368.2 million and $206.2 million as of September 30, 2020 and December 31, 2019, respectively, of which deferred revenue comprised approximately $349.1 million and $184.1 million, respectively. The increase in deferred revenue was primarily driven by timing of billings for projects in the Company’s Oil and Gas and Clean Energy and Infrastructure segments. For the three and nine month periods ended September 30, 2020, the Company recognized revenue of approximately $10.3 million and $139.6 million, respectively, related to amounts that were included in deferred revenue as of December 31, 2019, resulting primarily from the advancement of physical progress on the related projects during the period.

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
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 finance leases as of the dates indicated (in millions): September 30, December 31, Land $ 6.0 $ 4.9 Buildings and leasehold improvements 40.8 35.8 Machinery and equipment 1,834.7 1,659.4 Office furniture and equipment 216.3 197.3 Construction in progress 29.8 26.1 Total property and equipment $ 2,127.6 $ 1,923.5 Less accumulated depreciation and amortization (1,133.4) (1,017.7) Property and equipment, net $ 994.2 $ 905.8

Debt

Debt	9 Months Ended
	Sep. 30, 2020
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 September 30, December 31, Senior secured credit facility: September 19, 2024 Revolving loans $ 19.9 $ 339.2 Term loan 400.0 400.0 4.50% Senior Notes August 15, 2028 600.0 — 4.875% Senior Notes March 15, 2023 — 400.0 Finance lease and other obligations 300.2 305.6 Total debt obligations $ 1,320.1 $ 1,444.8 Less unamortized deferred financing costs (16.7) (12.4) Total debt, net of deferred financing costs $ 1,303.4 $ 1,432.4 Current portion of long-term debt 138.9 118.4 Long-term debt $ 1,164.5 $ 1,314.0 Issuance of 4.50% Senior Notes and Repurchase and Redemption of 4.875% Senior Notes On August 4, 2020, the Company issued $600 million aggregate principal amount of senior unsecured notes due August 15, 2028, which bear interest at a rate of 4.50% (the “4.50% Senior Notes”), at par in a private offering (the “Private Offering”). Interest on the 4.50% Senior Notes is payable semiannually in arrears on February 15 and August 15 of each year, beginning on February 15, 2021. The 4.50% Senior Notes are general senior unsecured obligations of the Company, and rank equal in right of payment with all of the Company’s existing and future senior unsecured indebtedness and senior in right of payment to all of the Company’s existing and future subordinated indebtedness. The 4.50% Senior Notes are effectively subordinated to all secured indebtedness of the Company, including its existing credit facilities, to the extent of the value of the assets securing such indebtedness. The 4.50% Senior Notes are fully and unconditionally guaranteed on a senior unsecured, joint and several basis by the Company’s wholly-owned domestic restricted subsidiaries that guarantee its existing credit facilities, subject to certain exceptions. The Company used a portion of the proceeds from the Private Offering to redeem all $400 million of its outstanding 4.875% Senior Notes due 2023 (the “ 4.875% Senior Notes”) on August 19, 2020 (the “Redemption Date”) at a redemption price equal to 100.813% of the principal amount of the 4.875% Senior Notes redeemed, plus accrued and unpaid interest to, but not including, the Redemption Date. The remaining net proceeds from the Private Offering were primarily used to repay revolving loans under the Company’s existing credit facilities. The Company has the option to redeem all or a portion of the 4.50% Senior Notes at any time on or after August 15, 2023 at the redemption prices specified in the indenture that governs the 4.50% Senior Notes (the “4.50% Senior Notes Indenture”), plus accrued and unpaid interest, if any, to (but excluding) the redemption date. In addition, at any time prior to August 15, 2023, the Company may redeem all or a part of the 4.50% Senior Notes at a redemption price equal to 100% of the principal amount of the 4.50% Senior Notes redeemed, plus accrued and unpaid interest, if any, to (but excluding) the redemption date, plus a “make-whole” premium. Further, prior to August 15, 2023, the Company may redeem up to 40% of the aggregate principal amount of the 4.50% Senior Notes using the net cash proceeds of certain equity offerings, at a redemption price equal to 104.500% of the principal amount of the 4.50% Senior Notes redeemed, plus accrued and unpaid interest, if any, to (but excluding) the date of redemption, subject to certain conditions. If the Company undergoes a change of control, as defined in the 4.50% Senior Notes Indenture, the Company must make an offer to repurchase all of the 4.50% Senior Notes then outstanding at a price equal to 101% of their principal amount, plus accrued and unpaid interest, if any, to (but excluding) the date of repurchase. The 4.50% Senior Notes Indenture, among other things, generally limits the ability of the Company and certain of its subsidiaries, subject to certain exceptions, to (i) create liens, (ii) pay dividends, (iii) acquire shares of capital stock, (iv) make certain investments and (v) effect mergers. The 4.50% Senior Notes Indenture provides for customary events of default, subject to customary grace and cure periods. Generally, if an event of default occurs and is continuing, the trustee or holders of at least 30% of the 4.50% Senior Notes then outstanding may declare the principal of, premium, if any, and accrued interest on all of the 4.50% Senior Notes immediately due and payable. Financing costs incurred in connection with the issuance of the 4.50% Senior Notes totaled approximately $8.9 million. These deferred financing costs, which are reflected as a reduction of the carrying amount of the 4.50% Senior Notes, will be amortized over the term of the 4.50% Senior Notes using the effective interest method. Management determined that the repurchase and redemption of the Company’s 4.875% Senior Notes should be accounted for as a debt extinguishment. Accordingly, the Company recorded a pre-tax debt extinguishment loss of approximately $5.6 million in the third quarter of 2020, including $3.3 million of early repayment premiums and $2.3 million of unamortized deferred financing costs. This loss is separately disclosed within the Company’s consolidated statements of operations. Senior Secured Credit Facility The Company’s senior secured credit facility (the “Credit Facility”) has aggregate borrowing commitments totaling approximately $1.75 billion as of September 30, 2020, composed of $1.35 billion of revolving commitments and a term loan of approximately $400 million. The term loan is subject to amortization in quarterly principal installments of $2.5 million commencing in December 2020, which amount will increase to $5.0 million commencing in December 2021. Quarterly principal installments on the term loan are subject to adjustment, if applicable, for certain prepayments. As of September 30, 2020 and December 31, 2019, outstanding revolving loans, which included $20 million and $138 million, respectively, of borrowings denominated in foreign currencies, accrued interest at weighted average rates of approximately 1.98% and 3.50% per annum, respectively. The term loan accrued interest at rates of 1.39% and 3.05% as of September 30, 2020 and December 31, 2019, respectively. Letters of credit of approximately $134.8 million and $98.0 million were issued as of September 30, 2020 and December 31, 2019, respectively. As of both September 30, 2020 and December 31, 2019, letter of credit fees accrued at 0.375% per annum for performance standby letters of credit and at 1.25% per annum 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 September 30, 2020 and December 31, 2019, availability for revolving loans totaled $1,195.3 million and $912.8 million, respectively, or up to $515.2 million and $552.0 million, respectively, for new letters of credit. Revolving loan borrowing capacity included $280.1 million and $162.4 million of availability in either Canadian dollars or Mexican pesos as of September 30, 2020 and December 31, 2019, respectively. The unused facility fee as of both September 30, 2020 and December 31, 2019 accrued at a rate of 0.20%. 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 and certain letter of credit issuances. As of September 30, 2020, outstanding borrowings under the Company’s other credit facilities totaled approximately $5.1 million and accrued interest at an average rate of 3.20%, and as of December 31, 2019, there were no outstanding borrowings. Additionally, the Company has a credit facility under which it may issue up to $50.0 million of performance standby letters of credit. As of September 30, 2020 and December 31, 2019, letters of credit issued under this facility totaled $18.2 million and $17.1 million, respectively, and accrued fees at 0.50% and 0.40% per annum, respectively. The Company’s other credit facilities are subject to customary provisions and covenants. Debt Covenants MasTec was in compliance with the provisions and covenants of its outstanding debt instruments as of September 30, 2020 and December 31, 2019. Additional Information As of September 30, 2020 and December 31, 2019, accrued interest payable, which is recorded within other accrued expenses in the consolidated balance sheets, totaled $5.7 million and $7.5 million, respectively. For additional information pertaining to the Company’s debt instruments, see Note 7 - Debt in the Company’s 2019 Form 10-K.

Lease Obligations

Lease Obligations	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Lease Obligations	Note 8 – Lease Obligations In the ordinary course of business, the Company enters into agreements that provide financing for machinery and equipment and for other of its facility, vehicle and equipment needs, including related party leases. As of September 30, 2020, the Company’s leases have remaining lease terms of up to nine years. Lease agreements may contain renewal clauses, which, if elected, generally extend the term of the lease for one to five years for both equipment and facility leases. Certain lease agreements may also contain options to purchase the leased property and/or options to terminate the lease. In addition, lease agreements may include periodic adjustments to payment amounts for inflation or other variables, or may require payments for taxes, insurance, maintenance or other expenses, which are generally referred to as non-lease components. The Company’s lease agreements do not contain significant residual value guarantees or material restrictive covenants. Finance Leases The gross amount of assets held under finance leases as of September 30, 2020 and December 31, 2019 totaled $536.8 million and $463.5 million, respectively. Assets held under finance leases, net of accumulated depreciation, totaled $406.5 million and $375.9 million as of September 30, 2020 and December 31, 2019, respectively. Depreciation expense associated with finance leases totaled $17.5 million and $13.1 million for the three month periods ended September 30, 2020 and 2019, respectively, and totaled $50.1 million and $34.2 million for the nine month periods ended September 30, 2020 and 2019, respectively. Operating Leases Operating lease additions for the three and nine month periods ended September 30, 2020 totaled $3.3 million and $16.6 million, respectively, and totaled $19.9 million and $86.4 million for the three and nine month periods ended September 30, 2019, respectively, excluding the effect of adoption of ASU 2016-02, Leases (Topic 842), of approximately $230.0 million. For the three month periods ended September 30, 2020 and 2019, rent expense for leases that have terms in excess of one year totaled approximately $25.6 million and $29.5 million, respectively, of which $2.3 million and $3.1 million, respectively, represented variable lease costs, and for the nine month periods ended September 30, 2020 and 2019, rent expense for such leases totaled approximately $87.7 million and $84.8 million, respectively, of which $8.0 million and $7.5 million, respectively, represented variable lease costs. The Company also incurred rent expense for leases with terms of one year or less totaling approximately $74.0 million and $144.0 million for the three month periods ended September 30, 2020 and 2019, respectively, and totaling approximately $224.4 million and $352.4 million for the nine month periods ended September 30, 2020 and 2019, respectively. Rent expense for operating leases is generally consistent with the amount of the related payments, which payments are included within operating activities in the consolidated statements of cash flows. Additional Lease Information Future minimum lease commitments as of September 30, 2020 were as follows (in millions): Finance Leases Operating 2020, remaining three months $ 41.6 $ 29.4 2021 131.7 72.6 2022 91.5 46.5 2023 38.9 23.8 2024 6.4 15.6 Thereafter 0.2 30.0 Total minimum lease payments $ 310.3 $ 217.9 Less amounts representing interest (15.2) (17.9) Total lease obligations, net of interest $ 295.1 $ 200.0 Less current portion 128.9 74.4 Long-term portion of lease obligations, net of interest $ 166.2 $ 125.6 As of September 30, 2020, finance leases had a weighted average remaining lease term of 2.5 years and a weighted average discount rate of 4.0%. Non-cancelable operating leases had a weighted average remaining lease term of 4.0 years and a weighted average discount rate of 3.9% as of September 30, 2020.

Stock-Based Compensation and Ot

Stock-Based Compensation and Other Employee Benefit Plans	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [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 September 30, 2020, there were approximately 3,011,000 shares available for future grant. Non-cash stock-based compensation expense under all plans totaled $5.6 million and $4.2 million for the three month periods ended September 30, 2020 and 2019, respectively, and totaled $15.5 million and $12.1 million for the nine month periods ended September 30, 2020 and 2019, respectively. Income tax benefits associated with stock-based compensation arrangements totaled $1.4 million and $1.0 million for the three month periods ended September 30, 2020 and 2019, respectively. For the nine month periods ended September 30, 2020 and 2019 income tax benefits totaled $3.6 million and $5.3 million, respectively, including net tax deficiencies related to the vesting of share-based payment awards totaling $0.1 million and net tax benefits totaling $2.3 million, respectively. Restricted Shares MasTec grants restricted stock awards and restricted stock units (together, “restricted shares”) to eligible participants, 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. As of September 30, 2020, total unearned compensation related to restricted shares was approximately $31.0 million, which is expected to be recognized over a weighted average period of approximately 2.0 years. The fair value of restricted shares that vested, which is based on the market price on the date of vesting, totaled $0.2 million for both the three month periods ended September 30, 2020 and 2019, and totaled $6.7 million and $14.1 million for the nine month periods ended September 30, 2020 and 2019, respectively. Activity, restricted shares: (a) Restricted Per Share Weighted Average Grant Date Fair Value Non-vested restricted shares, as of December 31, 2019 1,221,593 $ 45.36 Granted 936,946 27.15 Vested (183,885) 39.60 Canceled/forfeited (239,900) 58.96 Non-vested restricted shares, as of September 30, 2020 1,734,754 $ 34.26 (a) Includes 2,300 restricted stock units as of September 30, 2020. 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 Nine Months Ended September 30, 2020 2019 Cash proceeds (in millions) $ 5.5 $ 3.4 Common shares issued 193,655 87,014 Weighted average price per share $ 28.29 $ 39.23 Weighted average per share grant date fair value $ 8.61 $ 9.97

Other Retirement Plans

Other Retirement Plans	9 Months Ended
	Sep. 30, 2020
Retirement Benefits [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 a given time, and the plans in which they participate, vary depending upon the location and number of ongoing projects 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 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 September 30: 2020 1,452 1,469 $ 7.2 $ 1.7 $ 8.9 2019 3,814 5,349 $ 23.0 $ 1.2 $ 24.2 For the Nine Months Ended September 30: 2020 1,119 1,469 $ 19.5 $ 5.5 $ 25.0 2019 1,626 5,349 $ 51.7 $ 4.0 $ 55.7 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, the majority of which are within its oil and gas operations.

Equity

Equity	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Equity	Note 11 – Equity Share Activity The Company’s share repurchase programs provide for the repurchase of shares of MasTec 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 is determined based on market conditions, legal requirements, cash flow and liquidity needs and other factors. The Company’s share repurchase programs do not have an expiration date and 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. The Company may use either authorized and unissued shares or treasury shares to meet share issuance requirements. Treasury stock is recorded at cost. During the nine month period ended September 30, 2020, the Company repurchased 3.6 million shares of its common stock, substantially all of which were repurchased in the first quarter, for an aggregate purchase price totaling approximately $120.2 million. Of the total repurchased shares, 0.6 million were repurchased for $28.8 million under a $150 million share repurchase program that was established in September 2018 and completed in the first quarter of 2020, and 3.0 million were repurchased for $91.4 million under the Company’s December 2018 $100 million share repurchase program. For the nine month period ended September 30, 2019, share repurchases, which were completed in the first quarter under the Company’s September 2018 $150 million share repurchase program, totaled approximately $0.6 million. As of September 30, 2020, $158.6 million was available for future share repurchases under all of the Company’s open share repurchase programs, which included $8.6 million under the Company’s December 2018 share repurchase program, and the full amount of the Company’s March 2020 $150 million share repurchase program.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Note 12 – Income TaxesIn 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. For the three month periods ended September 30, 2020 and 2019, the Company’s consolidated effective tax rates were 25.7% and 25.0%, respectively. For the nine month periods ended September 30, 2020 and 2019, the Company’s consolidated effective tax rates were 22.7% and 24.5%, respectively. The Company’s effective tax rate for the nine month period ended September 30, 2020 benefited from the release of approximately $9.6 million of certain valuation allowances on Canadian deferred tax assets that were no longer necessary, as well as from adjustments related to the finalization of the Company’s 2019 tax returns. For the nine month period ended September 30, 2019, the Company’s effective tax rate was favorably affected by reduced foreign earnings, the recognition of $2.3 million of excess tax benefits from the vesting of share-based awards, adjustments from the finalization of the Company’s 2018 tax returns and the effects of foreign tax rate changes.

Segments and Related Informatio

Segments and Related Information	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Segment Reporting Disclosure	Note 13 – Segments and Related Information Segment Discussion The Company manages its operations under five operating segments, which represent its five reportable segments: (1) Communications; (2) Oil and Gas; (3) Electrical Transmission; (4) Clean Energy and Infrastructure and (5) Other. This structure is generally focused on broad end-user markets for the Company’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. The Company performs engineering, construction and maintenance services for 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 Clean Energy and Infrastructure segment primarily serves energy, utility and other end-markets through the installation and construction of power facilities, including from renewable sources, related electrical transmission infrastructure, ethanol/biofuel facilities and various types of heavy civil and industrial infrastructure. The Other segment includes certain equity investees, the services of which vary from those provided by the Company’s 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 its 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. Segment EBITDA is calculated in a manner consistent with consolidated EBITDA. 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, all of which are presented in millions. The tables below may contain slight summation differences due to rounding. For the Three Months Ended September 30, For the Nine Months Ended September 30, Revenue: 2020 2019 2020 2019 Communications (a) $ 645.4 $ 679.5 $ 1,943.8 $ 1,944.9 Oil and Gas 462.5 972.5 1,190.1 2,530.5 Electrical Transmission 128.5 103.0 380.7 298.3 Clean Energy and Infrastructure 468.9 261.7 1,181.4 701.3 Other 0.1 0.1 0.2 0.1 Eliminations (7.1) (0.2) (12.0) (1.1) Consolidated revenue $ 1,698.3 $ 2,016.6 $ 4,684.2 $ 5,474.0 (a) Revenue generated primarily by utilities customers represented 15.7% and 14.9% of Communications segment revenue for the three month periods ended September 30, 2020 and 2019, respectively, and represented 15.3% for both the nine month periods ended September 30, 2020 and 2019. For the Three Months Ended September 30, For the Nine Months Ended September 30, EBITDA: 2020 2019 2020 2019 Communications $ 79.6 $ 57.1 $ 206.8 $ 154.8 Oil and Gas 160.4 212.9 315.0 499.6 Electrical Transmission 9.1 7.8 14.2 20.3 Clean Energy and Infrastructure 34.4 2.3 69.5 14.4 Other 7.6 6.7 22.5 19.4 Corporate (37.5) (38.9) (100.6) (87.7) Consolidated EBITDA $ 253.6 $ 247.9 $ 527.4 $ 620.8 For the Three Months Ended September 30, For the Nine Months Ended September 30, Depreciation and Amortization: 2020 2019 2020 2019 Communications $ 21.1 $ 15.7 $ 62.1 $ 45.7 Oil and Gas 47.5 28.8 107.7 97.7 Electrical Transmission 6.2 5.1 18.6 14.8 Clean Energy and Infrastructure 5.0 3.3 13.7 9.7 Other 0.0 0.0 0.0 0.1 Corporate 2.8 2.3 8.5 6.2 Consolidated depreciation and amortization $ 82.6 $ 55.2 $ 210.6 $ 174.2 For the Three Months Ended September 30, For the Nine Months Ended September 30, EBITDA Reconciliation: 2020 2019 2020 2019 Income before income taxes $ 157.4 $ 173.4 $ 271.5 $ 388.5 Plus: Interest expense, net 13.6 19.3 45.4 58.2 Depreciation 71.4 50.5 182.2 160.0 Amortization of intangible assets 11.2 4.7 28.4 14.2 Consolidated EBITDA $ 253.6 $ 247.9 $ 527.4 $ 620.8 Foreign Operations and Other. MasTec operates in North America, primarily in the United States and Canada, and, to a lesser extent, in Mexico and the Caribbean. Revenue derived from U.S. operations totaled $1.7 billion and $2.0 billion for the three month periods ended September 30, 2020 and 2019, respectively, and totaled $4.6 billion and $5.3 billion for the nine month periods ended September 30, 2020 and 2019, respectively. Revenue derived from foreign operations totaled $18.2 million and $64.1 million for the three month periods ended September 30, 2020 and 2019, respectively, and totaled $77.8 million and $191.0 million for the nine month periods ended September 30, 2020 and 2019, respectively, the majority of which was derived from the Company’s Canadian operations in its Oil and Gas segment, and, to a lesser extent, from the Company’s wireless operations in Mexico. Long-lived assets held in the U.S. included property and equipment, net, of $971.4 million and $874.7 million as of September 30, 2020 and December 31, 2019, respectively, and, for the Company’s businesses in foreign countries, totaled $22.8 million and $31.1 million, respectively. Intangible assets and goodwill, net, related to the Company’s U.S. operations totaled approximately $1.4 billion as of both September 30, 2020 and December 31, 2019, and for the Company’s businesses in foreign countries, totaled approximately $50.3 million and $56.4 million as of September 30, 2020 and December 31, 2019, respectively. The majority of the Company’s long-lived and intangible assets and goodwill in foreign countries relate to its Canadian operations. As of September 30, 2020 and December 31, 2019, amounts due from customers from which foreign revenue was derived accounted for approximately 4% and 5%, respectively, of the Company’s consolidated net accounts receivable position, which represents accounts receivable, net, less deferred revenue. Revenue from governmental entities for each of the three and nine month periods ended September 30, 2020 totaled approximately 2% of total revenue, and for each of the three and nine month periods ended September 30, 2019 totaled approximately 1%. Substantially all revenue from governmental entities was derived from the Company’s U.S. operations. Significant Customers Revenue concentration information for significant customers as a percentage of total consolidated revenue was as follows: For the Three Months Ended September 30, For the Nine Months Ended September 30, Customer: 2020 2019 2020 2019 AT&T (including DIRECTV ® ) (a) 15% 18% 19% 20% Equitrans Midstream Corporation (b) 3% 17% 2% 12% (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; (ii) wireline/fiber; and (iii) various install-to-the-home businesses, including DIRECTV ® . Revenue from AT&T is included within the Communications segment. (b) The Company's relationship with Equitrans Midstream Corporation and its affiliates is based upon various construction contracts for pipeline activities, for which the related revenue is included in the Oil and Gas segment.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
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 and surety bond providers and in support of performance under certain contracts as well as certain obligations associated with the Company’s equity investments and other strategic arrangements, 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 September 30, 2020 and December 31, 2019, there were $153.0 million and $115.1 million, respectively, of letters of credit issued under the Company’s credit facilities. The Company is not aware of any material claims relating to its outstanding letters of credit as of September 30, 2020 or December 31, 2019. 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 its projects. 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 its subcontractors and vendors. If the Company fails to perform under a contract or to pay its 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 September 30, 2020 and December 31, 2019, outstanding performance and payment bonds approximated $640.1 million and $551.4 million, respectively, and estimated costs to complete projects secured by these bonds totaled $226.3 million and $194.7 million as of September 30, 2020 and December 31, 2019, respectively. Investment and Strategic Arrangements. 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, as well as a 50% undivided interest in a civil construction 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 September 30, 2020, the Company was not aware of any material future claims against it in connection with these arrangements. Included in the Company’s cash balances as of September 30, 2020 and December 31, 2019 are amounts held by entities that are proportionately consolidated totaling $8.4 million and $13.1 million, respectively. These amounts are available to support the operations of those entities, but are not available for the Company’s other operations. The Company has other investment and strategic arrangements, under which it may incur costs or provide financing, performance, financial and/or other guarantees. See Note 4 - Fair Value of Financial Instruments regarding the Company’s other investment and strategic 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 September 30, 2020 and December 31, 2019, MasTec’s estimated liability for unpaid claims and associated expenses, including incurred but not reported losses related to these policies, totaled $129.0 million and $123.4 million, respectively, of which $85.9 million and $87.3 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 $4.1 million and $4.2 million as of September 30, 2020 and December 31, 2019, respectively. The Company is required to post collateral, generally in the form of letters of credit, surety bonds and cash to certain of its insurance carriers. Insurance-related letters of credit for the Company’s workers’ compensation, general liability and automobile liability policies amounted to $59.3 million and $64.0 million as of September 30, 2020 and December 31, 2019, respectively. Outstanding surety bonds related to self-insurance programs amounted to $37.4 million and $38.5 million as of September 30, 2020 and December 31, 2019, respectively. 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 MEPPs, 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 September 30, 2020, 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 or increased contributions on underfunded plans. 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, which could be negatively affected by economic and market conditions, 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 September 30, 2020 and December 31, 2019, the Company was not aware of any material asserted or unasserted claims in connection with these indemnity obligations. Other Guarantees. From time to time in the ordinary course of its business, 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. 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. Warranty claims have historically not been material. Concentrations of Risk. The Company had approximately 435 customers for the nine month period ended September 30, 2020. As of September 30, 2020, two customers each accounted for approximately 15% and 13%, respectively, of the Company’s consolidated net accounts receivable position, which represents accounts receivable, net, less deferred revenue. As of December 31, 2019, three customers each accounted for approximately 17%, 13% and 11%, respectively, of the Company’s consolidated net accounts receivable position. In addition, the Company derived 63% and 65%, respectively, of its revenue from its top ten customers for the three month periods ended September 30, 2020 and 2019, and derived 61% and 63%, respectively, of its revenue from its top ten customers for the nine month periods ended September 30, 2020 and 2019.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2020
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, including ancillary construction services, project-related site restoration and marketing and business development activities, from a number of different vendors on a non-exclusive basis, and from time to time, rents equipment to, or performs construction services on behalf of, entities in which members of subsidiary management have ownership or commercial interests. For the three month periods ended September 30, 2020 and 2019, such payments to related party entities totaled approximately $23.8 million and $25.5 million, respectively, and for the nine month periods ended September 30, 2020 and 2019, totaled approximately $65.3 million and $71.8 million, respectively. Related payables totaled approximately $5.9 million and $14.7 million as of September 30, 2020 and December 31, 2019, respectively. Revenue from such related party arrangements totaled approximately $0.9 million and $0.7 million for the three month periods ended September 30, 2020 and 2019, respectively, and totaled $3.2 million and $1.6 million for the nine month periods ended September 30, 2020 and 2019, respectively. As of September 30, 2020, related amounts receivable, net, totaled approximately $0.5 million, and as of December 31, 2019, were de minimis. In 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. Amounts outstanding for advances made by the Company on behalf of this entity were de minimis as of September 30, 2020 and totaled approximately $0.5 million, net, as of December 31, 2019, respectively, which are expected to be settled under customary terms associated with the related purchase agreement. The Company rents and leases equipment and purchases equipment supplies and servicing 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 and an entity that is owned by the Mas family are minority owners. MasTec paid CCI, net of rebates, $1.8 million and $7.7 million, respectively, for the three month periods ended September 30, 2020 and 2019, and $3.2 million and $23.6 million, respectively, for the nine month periods ended September 30, 2020 and 2019. As of September 30, 2020 and December 31, 2019, amounts payable to CCI, net of rebates receivable, totaled approximately $1.6 million and $0.2 million, respectively. The Company has also rented equipment to CCI. Revenue from equipment rentals to CCI totaled approximately $0.2 million and $0.8 million for the three and nine month periods ended September 30, 2020, respectively, and related receivables totaled approximately $0.2 million as of September 30, 2020. 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. No subcontracting expenses were incurred by MasTec for the three month period ended September 30, 2020, and for the three month period ended September 30, 2019, MasTec incurred subcontracting expenses of approximately $3.1 million. For the nine month periods ended September 30, 2020 and 2019, MasTec incurred subcontracting expenses of approximately $0.6 million and $9.3 million, respectively. As of September 30, 2020 and December 31, 2019, related amounts payable totaled approximately $0.1 million and $0.2 million, respectively. 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 September 30, 2020 and 2019, MasTec paid approximately $0.6 million, related to this leasing arrangement, and for the nine month periods ended September 30, 2020 and 2019, paid approximately $1.9 million and $2.0 million, respectively. MasTec performs construction services on behalf of a professional Miami soccer franchise (the “Franchise”) in which Jorge Mas and José R. Mas are minority owners. Services provided by MasTec include the construction of a soccer facility and stadium as well as wireless infrastructure services. MasTec charged approximately $0.7 million and $5.2 million under these arrangements for the three month periods ended September 30, 2020 and 2019, respectively, and charged approximately $6.2 million and $7.4 million for the nine month periods ended September 30, 2020 and 2019, respectively. Amounts outstanding as of September 30, 2020 and December 31, 2019 totaled approximately $0.7 million and $3.9 million, respectively. Payments for other expenses related to the Franchise totaled $0.2 million for the nine month period ended September 30, 2020. MasTec leases employees and provides satellite communications services to a customer in which Jorge Mas and José R. Mas own a majority interest. Charges to this customer totaled approximately $0.3 million for both the three month periods ended September 30, 2020 and 2019, and for the nine month periods ended September 30, 2020 and 2019, totaled approximately $1.0 million and $1.1 million, respectively. As of September 30, 2020 and December 31, 2019, outstanding receivables related to these arrangements totaled approximately $1.0 million and $0.8 million, respectively. The Company has a 25% interest in an entity associated with an acquisition, under which the acquired business and the entity have a subcontracting arrangement. The Company’s interest in this entity is accounted for as an equity method investment. As of September 30, 2020, the Company’s net investment in this entity was a liability of approximately $1.7 million, which net amount includes approximately $2.2 million of accounts receivable, net, less deferred revenue, related to the subcontracting arrangement. Additionally, the Company has a strategic arrangement with an entity associated with a separate acquisition, in which members of management of the acquired business have an ownership interest. For both the three and nine month periods ended September 30, 2020, approximately $0.6 million, net, of income was recognized in connection with this arrangement, and amounts receivable totaled $0.2 million as of September 30, 2020. In addition, for the nine month period ended September 30, 2020, the Company advanced $1.2 million on behalf of this entity, of which $0.6 million was outstanding as of September 30, 2020. Split Dollar Agreements MasTec has split dollar life insurance agreements with trusts, of which Jorge Mas or José R. Mas is a trustee. For both the three month periods ended September 30, 2020 and 2019, the Company paid $0.6 million in connection with the agreements for Jorge Mas, and no payments were made for José R. Mas. For both the nine month periods ended September 30, 2020 and 2019, the Company paid $1.1 million in connection with the split dollar agreements for Jorge Mas, and paid $0.7 million for both the nine month periods ended September 30, 2020 and 2019 for José R. Mas. As of September 30, 2020 and December 31, 2019, life insurance assets associated with these agreements totaled approximately $22.2 million and $20.3 million, respectively.

Business, Basis of Presentati_2

Business, Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements are unaudited and 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 consolidated balance sheet as of December 31, 2019 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 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, 2019 contained in the Company’s 2019 Annual Report on Form 10-K (the “2019 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. When necessary, 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 consolidated financial statements are adequate to make the information not misleading.
Reclassifications	When necessary, certain prior year amounts have been reclassified to conform to the current period presentation.
Principles of Consolidation	Principles of ConsolidationThe accompanying 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, except for mandatorily redeemable non-controlling interests, which are recorded within liabilities. 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 over which it has the ability to exert significant influence, are accounted for using the equity method of accounting. For equity investees in which the Company has an undivided interest in the assets, liabilities and profits or losses of an unincorporated entity, but does not exercise control over the entity, the Company consolidates its proportional interest in the accounts of the entity.
Equity Method Investments	The Company’s investments in entities for which the Company does not have a controlling interest, but over which it has the ability to exert significant influence, are accounted for using the equity method of accounting.
Unincorporated Entities, Proportional 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 does not exercise control over the entity, the Company consolidates its proportional interest in the accounts of the entity
Translation of Foreign Currencies	Translation of Foreign CurrenciesThe 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 included 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, including the potential future effects of the COVID-19 pandemic and other relevant global events. These estimates form the basis for making judgments about the Company’s operating results and the carrying values of assets and liabilities that are not readily apparent from other sources. 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. 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 and probability of variable consideration included in the contract transaction price; fair value estimates, including those related to acquisitions, valuations of goodwill and intangible assets, acquisition-related contingent consideration and other liabilities, equity investments and other long-lived assets; allowances for credit losses; 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.
COVID-19 Disclosure	COVID-19 Pandemic During March 2020, the World Health Organization declared a global pandemic related to the rapidly growing outbreak of a novel strain of coronavirus (“COVID-19”). The COVID-19 pandemic has significantly affected economic conditions in the United States and internationally, as national, state and local governments reacted to the public health crisis by requiring mitigation measures resulting in workforce, supply chain and other market disruptions that have created significant uncertainties in the U.S. and global economies and disrupted business activities for an uncertain period of time. Although certain jurisdictions have subsequently taken steps to lift or ease such restrictions to various degrees, such lifting or easing could subsequently be reversed, or new restrictions imposed, due to a rise in cases of COVID-19. Most of the Company’s construction services have been and currently are deemed essential under state and local pandemic mitigation orders, and all of its business segments continue to operate. Where safe and possible, the Company has generally been directed by its customers to maintain normal work schedules. Management’s top priority has been to take appropriate actions to protect the health and safety of its employees, customers and business partners, including adjusting its standard operating procedures to respond to evolving health guidelines. The COVID-19 pandemic has had a negative impact on the Company’s operations and is expected to have some continued negative impact. These impacts include lost productivity from governmental permitting approval delays, reduced crew productivity due to social distancing, other mitigation measures or other factors, the health and availability of work crews or other key personnel, including subcontractors or supply chain disruptions, and/or delayed project start dates or project shutdowns or cancellations that may be mandated or requested by governmental authorities or others, all of which could result in lower revenue or higher operating costs and/or create lower levels of overhead cost absorption. In response to the COVID-19 pandemic, the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was signed into law on March 27, 2020. The CARES Act provides for various tax relief and incentive measures, including provisions permitting the deferral and/or reduction of certain federal and payroll tax amounts. The Company has pursued certain of these relief provisions, and for the nine month period ended September 30, 2020, has deferred approximately $22 million of payroll taxes, net. The Company will continue to evaluate the potential effects of the CARES Act on its financial position, results of operations and cash flows. Management believes that it is taking appropriate steps to mitigate any potential impact to the Company; however, given the uncertainty regarding the potential effects of the COVID-19 pandemic, any future impacts cannot be quantified or predicted with specificity.
Revenue Recognition	Revenue Recognition The Company recognizes revenue from contracts with customers under Accounting Standards Codification (“ASC”) Topic 606 (“Topic 606”). 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. Revenue is primarily recognized by the Company over time utilizing the cost-to-cost measure of progress, which best depicts the continuous transfer of control of goods or services to the customer, and correspondingly, when performance obligations are satisfied for the related contracts. Contracts. The Company derives revenue primarily from construction projects performed under: (i) 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 either a time and materials, or a fixed price per unit basis; and (ii) 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 projects performed under master service and other service agreements totaled 32% of consolidated revenue for both the three month periods ended September 30, 2020 and 2019, and totaled 36% and 35% for the nine month periods ended September 30, 2020 and 2019, respectively. For certain master service and other service agreements under which the Company 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 4% of consolidated revenue for both the three month periods ended September 30, 2020 and 2019, and accounted for approximately 5% for both the nine month periods ended September 30, 2020 and 2019. Substantially all of the Company’s other revenue is recognized over time. The total contract transaction price and cost estimation processes used 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 the Company’s 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 nine month periods ended September 30, 2020 and 2019, 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, 2019 and 2018. Revenue recognized for the three month periods ended September 30, 2020 and 2019 as a result of changes in total contract transaction price estimates, including for variable consideration, from performance obligations satisfied or partially satisfied in prior periods, totaled approximately $8.8 million and $13.3 million, respectively, and totaled $11.5 million and $52.2 million for the nine month periods ended September 30, 2020 and 2019, respectively. The Company may incur certain costs that can be capitalized, such as initial set-up or mobilization costs. Such costs, which are amortized over the life of the respective projects, were not material as of September 30, 2020 or December 31, 2019. 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 vast majority of the Company’s performance obligations are completed within one year. Remaining performance obligations represent the amount of unearned transaction prices under contracts for which work is wholly or partially unperformed, including the Company’s share of unearned transaction prices from its proportionately consolidated non-controlled joint ventures. As of September 30, 2020, the amount of the Company’s remaining performance obligations was $5.3 billion. Based on current expectations, the Company expects to recognize approximately $1.6 billion of its remaining performance obligations as revenue during 2020, with the remainder to be recognized primarily in 2021. Variable Consideration. Transaction prices for the Company’s contracts may include variable consideration, which comprises items such as change orders, claims and incentives. Management estimates variable consideration for a performance obligation utilizing estimation methods that it believes best predict the amount of consideration to which the Company will be entitled. Management’s estimates of variable consideration and the determination of whether to include estimated amounts in transaction prices 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 at the time of the estimate. To the extent unapproved change orders, claims and other variable consideration reflected in transaction prices are not resolved in the Company’s favor, or to the extent incentives reflected in transaction prices are not earned, there could be reductions in, or reversals of, previously recognized revenue. As of September 30, 2020 and December 31, 2019, the Company included approximately $50 million and $27 million, respectively, of change orders and/or claims in transaction prices for certain contracts that were in the process of being resolved in the ordinary course of business, including through negotiation, arbitration and other proceedings. These transaction price adjustments, when earned, are included within contract assets or accounts receivable, net of allowance, as appropriate. As of both September 30, 2020 and December 31, 2019, these change orders and/or claims were primarily related to certain projects in the Company’s Oil and Gas and Electrical Transmission segments. 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 agreement by customers could be higher or lower than such estimated amounts.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements See 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 2019 Form 10-K. Accounting Pronouncements Adopted in 2020 In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40) Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (“ASU 2018-15”) to reduce diversity in practice in accounting for the costs of implementing cloud computing arrangements that are service contracts. ASU 2018-15 aligns the requirements for capitalizing implementation costs incurred in a cloud computing arrangement that is a service contract with the requirements for internal-use software. Accounting for the service element of the cloud computing arrangement is not affected by the new guidance. Under ASU 2018-15, amortization expense, payments for and asset balances related to such capitalized implementation costs are to be presented within the same line items of the entity’s statements of operations, cash flows and balance sheets, respectively, as the related service fee activity and balances would be presented. ASU 2018-15, which the Company adopted on a prospective basis during the first quarter of 2020, did not have a material effect on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) Disclosure Framework - Changes to the Disclosure Requiremen ts for Fair Value Measurement (“ASU 2018-13”). ASU 2018-13, which is intended to improve the effectiveness of fair value measurement disclosures, modifies the disclosure requirements for certain estimates and assumptions used in determining the fair value of assets and liabilities. ASU 2018-13, which the Company adopted during the first quarter of 2020, did not have a material effect on the Company’s consolidated financial statements. See Note 4 - Fair Value of Financial Instruments for disclosure updates pertaining to significant unobservable inputs used to develop fair value estimates for certain of the Company’s Level 3 financial instruments. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments . This ASU, together with its related clarifying ASUs (collectively, “ASU 2016-13”), introduced an expected credit loss methodology for the measurement and recognition of credit losses on most financial assets, including financial assets arising from revenue transactions, such as accounts receivable and contract assets. The new expected credit loss methodology, which is based on historical experience, current conditions and reasonable and supportable forecasts, replaced the incurred loss model for measuring and recognizing expected credit losses. The Company adopted this ASU in the first quarter of 2020 and incorporated this guidance into its methodology for estimating its accounts receivable allowances. Based on historical trends, the financial condition of the Company’s customers and management’s expectations of economic and industry factors affecting the Company’s customers, ASU 2016-13 did not have a material effect on the Company’s consolidated financial statements upon adoption. Future credit loss expectations could be affected by changes in estimates or developing trends, including from changes in credit quality of the Company’s customers, changes in specific risks associated with the Company’s financial assets, or from changes in management’s expectations of future economic and industry conditions or other factors. Management actively monitors the economic environment, including any potential effects from the COVID-19 pandemic and/or volatility in the oil and gas markets on the credit quality of the Company’s customers and/or its financial assets. For additional information about the Company’s accounts receivable and related allowances, see Note 5 - Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 Net income attributable to MasTec: Net income - basic and diluted (a) $ 116,491 $ 128,596 $ 209,726 $ 291,418 Weighted average shares outstanding: Weighted average shares outstanding - basic 72,138 75,217 72,971 75,131 Dilutive common stock equivalents (b) 957 717 816 629 Weighted average shares outstanding - diluted 73,095 75,934 73,787 75,760 (a) Calculated as total net income less amounts attributable to non-controlling interests. (b) For the nine month period ended September 30, 2020, there were 58,759 anti-dilutive common stock equivalents.

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill by Segment	The following table provides balances for goodwill by reportable segment as of September 30, 2020 (in millions): Communications Oil and Gas Electrical Clean Energy and Infrastructure Total Goodwill Goodwill, gross $ 551.4 $ 496.0 $ 150.1 $ 152.8 $ 1,350.3 Accumulated impairment loss — (118.6) — — (118.6) Goodwill, net $ 551.4 $ 377.4 $ 150.1 $ 152.8 $ 1,231.7
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 Pre-Qualifications Other (a) Total Other intangible assets, gross, as of December 31, 2019 $ 34.5 $ 72.9 $ 286.5 $ — $ 26.3 $ 420.2 Accumulated amortization (191.2) — (17.5) (208.7) Other intangible assets, net, as of December 31, 2019 $ 34.5 $ 72.9 $ 95.3 $ — $ 8.8 $ 211.5 Additions from new business combinations — — 9.7 — 0.1 9.8 Classification changes (b) — (69.8) — 69.8 — — Measurement period adjustments (c) — — (0.2) — — (0.2) Currency translation adjustments — (3.1) — 2.1 — (1.0) Amortization expense (19.8) (7.1) (1.5) (28.4) Other intangible assets, net, as of September 30, 2020 $ 34.5 $ — $ 85.0 $ 64.8 $ 7.4 $ 191.7 (a) Consists principally of trade names and non-compete agreements. (b) In connection with its first quarter assessment of goodwill and indefinite-lived intangible assets, management reassessed the indefinite-life classification of its two pre-qualification intangible assets. Management determined that, based on changes in the assets’ characteristics, including current and expected changes in the customer mix of the associated reporting units, a finite-life classification for these assets was more appropriate. As a result, in the first quarter of 2020, the Company changed the classification of these pre-qualification intangible assets from indefinite-lived to finite-lived and began amortizing them on an accelerated basis, with an estimated remaining weighted average useful life of approximately 12 years. (c) Represents adjustments to preliminary estimates of fair value within the measurement period of up to one year from the date of acquisition.

Accounts Receivable, Net of A_2

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2020
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): September 30, December 31, Contract billings $ 939.6 $ 860.4 Less allowance (22.5) (10.1) Accounts receivable, net of allowance $ 917.1 $ 850.3 Retainage 313.1 345.2 Unbilled receivables 706.8 679.4 Contract assets $ 1,019.9 $ 1,024.6

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2020
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 finance leases as of the dates indicated (in millions): September 30, December 31, Land $ 6.0 $ 4.9 Buildings and leasehold improvements 40.8 35.8 Machinery and equipment 1,834.7 1,659.4 Office furniture and equipment 216.3 197.3 Construction in progress 29.8 26.1 Total property and equipment $ 2,127.6 $ 1,923.5 Less accumulated depreciation and amortization (1,133.4) (1,017.7) Property and equipment, net $ 994.2 $ 905.8

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, December 31, Senior secured credit facility: September 19, 2024 Revolving loans $ 19.9 $ 339.2 Term loan 400.0 400.0 4.50% Senior Notes August 15, 2028 600.0 — 4.875% Senior Notes March 15, 2023 — 400.0 Finance lease and other obligations 300.2 305.6 Total debt obligations $ 1,320.1 $ 1,444.8 Less unamortized deferred financing costs (16.7) (12.4) Total debt, net of deferred financing costs $ 1,303.4 $ 1,432.4 Current portion of long-term debt 138.9 118.4 Long-term debt $ 1,164.5 $ 1,314.0

Lease Obligations (Tables)

Lease Obligations (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Schedule of Future Minimum Lease Commitments, Finance Leases	Future minimum lease commitments as of September 30, 2020 were as follows (in millions): Finance Leases Operating 2020, remaining three months $ 41.6 $ 29.4 2021 131.7 72.6 2022 91.5 46.5 2023 38.9 23.8 2024 6.4 15.6 Thereafter 0.2 30.0 Total minimum lease payments $ 310.3 $ 217.9 Less amounts representing interest (15.2) (17.9) Total lease obligations, net of interest $ 295.1 $ 200.0 Less current portion 128.9 74.4 Long-term portion of lease obligations, net of interest $ 166.2 $ 125.6
Schedule of Future Minimum Lease Commitments, Operating Leases	Future minimum lease commitments as of September 30, 2020 were as follows (in millions): Finance Leases Operating 2020, remaining three months $ 41.6 $ 29.4 2021 131.7 72.6 2022 91.5 46.5 2023 38.9 23.8 2024 6.4 15.6 Thereafter 0.2 30.0 Total minimum lease payments $ 310.3 $ 217.9 Less amounts representing interest (15.2) (17.9) Total lease obligations, net of interest $ 295.1 $ 200.0 Less current portion 128.9 74.4 Long-term portion of lease obligations, net of interest $ 166.2 $ 125.6

Stock-Based Compensation and _2

Stock-Based Compensation and Other Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Schedule of Activity, Restricted Shares	Activity, restricted shares: (a) Restricted Per Share Weighted Average Grant Date Fair Value Non-vested restricted shares, as of December 31, 2019 1,221,593 $ 45.36 Granted 936,946 27.15 Vested (183,885) 39.60 Canceled/forfeited (239,900) 58.96 Non-vested restricted shares, as of September 30, 2020 1,734,754 $ 34.26 (a) Includes 2,300 restricted stock units as of September 30, 2020.
Schedule of Employee Stock Purchase Plans	The following table provides details pertaining to the Company’s ESPPs for the periods indicated: For the Nine Months Ended September 30, 2020 2019 Cash proceeds (in millions) $ 5.5 $ 3.4 Common shares issued 193,655 87,014 Weighted average price per share $ 28.29 $ 39.23 Weighted average per share grant date fair value $ 8.61 $ 9.97

Other Retirement Plans (Tables)

Other Retirement Plans (Tables)	9 Months Ended
	Sep. 30, 2020
Retirement Benefits [Abstract]
Schedule of Covered Employees and Contributions, Multiemployer Plans	Total contributions to multiemployer plans and the related number of employees covered by these plans 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 September 30: 2020 1,452 1,469 $ 7.2 $ 1.7 $ 8.9 2019 3,814 5,349 $ 23.0 $ 1.2 $ 24.2 For the Nine Months Ended September 30: 2020 1,119 1,469 $ 19.5 $ 5.5 $ 25.0 2019 1,626 5,349 $ 51.7 $ 4.0 $ 55.7

Segments and Related Informat_2

Segments and Related Information (Tables)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Schedule of Financial Information by Reportable Segment	For the Three Months Ended September 30, For the Nine Months Ended September 30, Revenue: 2020 2019 2020 2019 Communications (a) $ 645.4 $ 679.5 $ 1,943.8 $ 1,944.9 Oil and Gas 462.5 972.5 1,190.1 2,530.5 Electrical Transmission 128.5 103.0 380.7 298.3 Clean Energy and Infrastructure 468.9 261.7 1,181.4 701.3 Other 0.1 0.1 0.2 0.1 Eliminations (7.1) (0.2) (12.0) (1.1) Consolidated revenue $ 1,698.3 $ 2,016.6 $ 4,684.2 $ 5,474.0 (a) Revenue generated primarily by utilities customers represented 15.7% and 14.9% of Communications segment revenue for the three month periods ended September 30, 2020 and 2019, respectively, and represented 15.3% for both the nine month periods ended September 30, 2020 and 2019. For the Three Months Ended September 30, For the Nine Months Ended September 30, EBITDA: 2020 2019 2020 2019 Communications $ 79.6 $ 57.1 $ 206.8 $ 154.8 Oil and Gas 160.4 212.9 315.0 499.6 Electrical Transmission 9.1 7.8 14.2 20.3 Clean Energy and Infrastructure 34.4 2.3 69.5 14.4 Other 7.6 6.7 22.5 19.4 Corporate (37.5) (38.9) (100.6) (87.7) Consolidated EBITDA $ 253.6 $ 247.9 $ 527.4 $ 620.8 For the Three Months Ended September 30, For the Nine Months Ended September 30, Depreciation and Amortization: 2020 2019 2020 2019 Communications $ 21.1 $ 15.7 $ 62.1 $ 45.7 Oil and Gas 47.5 28.8 107.7 97.7 Electrical Transmission 6.2 5.1 18.6 14.8 Clean Energy and Infrastructure 5.0 3.3 13.7 9.7 Other 0.0 0.0 0.0 0.1 Corporate 2.8 2.3 8.5 6.2 Consolidated depreciation and amortization $ 82.6 $ 55.2 $ 210.6 $ 174.2
Reconciliation of Consolidated Income before Income Taxes to EBITDA	For the Three Months Ended September 30, For the Nine Months Ended September 30, EBITDA Reconciliation: 2020 2019 2020 2019 Income before income taxes $ 157.4 $ 173.4 $ 271.5 $ 388.5 Plus: Interest expense, net 13.6 19.3 45.4 58.2 Depreciation 71.4 50.5 182.2 160.0 Amortization of intangible assets 11.2 4.7 28.4 14.2 Consolidated EBITDA $ 253.6 $ 247.9 $ 527.4 $ 620.8

Business, Basis of Presentati_3

Business, Basis of Presentation and Significant Accounting Policies (Narrative) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)numberOfSegments	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Number of reportable segments | numberOfSegments			5
Revenue [Line Items]
Revenue recognition, performance obligations satisfied in previous periods, revenue recognized (in dollars)	$ 8.8	$ 13.3	$ 11.5	$ 52.2
Contract with customer, unapproved change orders and/or claims, amount (in dollars)	50		50		$ 27
Revenue [Table]
Accrued Payroll Taxes	$ 22		$ 22
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
Revenue Benchmark [Member] | Concentration Risk from Type of Arrangement [Member] | Master Service and Other Service Agreements [Member]
Revenue [Line Items]
Concentration risk, percentage of total	32.00%	32.00%	36.00%	35.00%
Revenue Benchmark [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	4.00%	4.00%	5.00%	5.00%

Business, Basis of Presentati_4

Business, Basis of Presentation and Significant Accounting Policies (Remaining Performance Obligations) (Narrative) (Details) $ in Billions	Sep. 30, 2020USD ($)
Accounting Policies [Abstract]
Revenue recognition, remaining performance obligations, contract price allocated (in dollars)	$ 5.3
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Accounting Policies [Abstract]
Revenue recognition, remaining performance obligations, contract price allocated (in dollars)	$ 1.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year

Business, Basis of Presentati_5

Business, Basis of Presentation and Significant Accounting Policies (Accounting Pronouncements Adopted) (Narrative) (Details)	Sep. 30, 2020
ASU 2018-15 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2018-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) shares in Millions	9 Months Ended
	Sep. 30, 2020shares
Earnings Per Share [Abstract]
Treasury stock acquired (in shares)	3.6
Effect of share repurchases, decrease in weighted average shares outstanding (in shares)	2.6

Earnings Per Share (Schedule of

Earnings Per Share (Schedule of Earnings Per Share Information) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net income attributable to MasTec:
Net income - basic (in dollars)	$ 116,491	$ 128,596	$ 209,726	$ 291,418
Net income - diluted (in dollars)	$ 116,491	$ 128,596	$ 209,726	$ 291,418
Weighted average shares outstanding:
Weighted average shares outstanding - basic	72,138,000	75,217,000	72,971,000	75,131,000
Dilutive common stock equivalents (in shares)	957,000	717,000	816,000	629,000
Weighted average shares outstanding - diluted	73,095,000	75,934,000	73,787,000	75,760,000
Anti-dilutive common stock (in shares)			58,759

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Schedule of Goodwill by Segment) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill, gross	$ 1,350,300
Accumulated impairment loss	(118,600)
Goodwill, net	1,231,717	$ 1,221,440
Communications [Member]
Goodwill [Line Items]
Goodwill, gross	551,400
Accumulated impairment loss	0
Goodwill, net	551,400
Oil and Gas [Member]
Goodwill [Line Items]
Goodwill, gross	496,000
Accumulated impairment loss	(118,600)
Goodwill, net	377,400
Electrical Transmission [Member]
Goodwill [Line Items]
Goodwill, gross	150,100
Accumulated impairment loss	0
Goodwill, net	150,100
Clean Energy and Infrastructure [Member]
Goodwill [Line Items]
Goodwill, gross	152,800
Accumulated impairment loss	0
Goodwill, net	$ 152,800

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
Goodwill [Line Items]
Goodwill, acquired during period	$ 5.2
Goodwill, measurement period adjustments	5.4
Goodwill, Gross [Member]
Goodwill [Line Items]
Goodwill, currency translation gains (losses)	(3.2)
Goodwill, Accumulated Impairment Loss [Member]
Goodwill [Line Items]
Goodwill, currency translation gains (losses)	$ 2.9

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets (Rollforward of Other Intangible Assets) (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Sep. 30, 2020	Dec. 31, 2019
Other Intangible Assets [Line Items]
Other intangible assets, gross			$ 420,200
Accumulated amortization			(208,700)
Other Intangible Assets [Rollforward]
Other intangible assets, net, beginning balance	$ 211,528	$ 211,528
Additions from new business combinations		9,800
Transfers in (out)		0
Measurement period adjustments		(200)
Currency translation adjustments		(1,000)
Amortization expense		(28,400)
Other intangible assets, net, ending balance		191,673
Customer Relationships and Backlog [Member]
Other Intangible Assets [Line Items]
Other intangible assets, amortizing, gross			286,500
Accumulated amortization			(191,200)
Other Intangible Assets [Rollforward]
Other intangible assets, net, amortizing, beginning balance	95,300	95,300
Additions from new business combinations, amortizing intangible assets		9,700
Transfers in (out), amortizing intangible assets		0
Measurement period adjustments, amortizing intangible assets		(200)
Currency translation adjustments, amortizing intangible assets		0
Amortization expense		(19,800)
Other intangible assets, net, amortizing, ending balance		85,000
Pre-Qualifications [Member]
Other Intangible Assets [Line Items]
Other intangible assets, amortizing, gross			0
Accumulated amortization			0
Other Intangible Assets [Rollforward]
Other intangible assets, net, amortizing, beginning balance	$ 0	0
Additions from new business combinations, amortizing intangible assets		0
Transfers in (out), amortizing intangible assets		69,800
Measurement period adjustments, amortizing intangible assets		0
Currency translation adjustments, amortizing intangible assets		2,100
Amortization expense		(7,100)
Other intangible assets, net, amortizing, ending balance		64,800
Pre-Qualifications [Member] | Weighted Average [Member]
Other Intangible Assets [Rollforward]
Remaining amortization period (in years)	12 years
Other Amortizing Intangible Assets [Member]
Other Intangible Assets [Line Items]
Other intangible assets, amortizing, gross			26,300
Accumulated amortization			(17,500)
Other Intangible Assets [Rollforward]
Other intangible assets, net, amortizing, beginning balance	$ 8,800	8,800
Additions from new business combinations, amortizing intangible assets		100
Transfers in (out), amortizing intangible assets		0
Measurement period adjustments, amortizing intangible assets		0
Currency translation adjustments, amortizing intangible assets		0
Amortization expense		(1,500)
Other intangible assets, net, amortizing, ending balance		7,400
Trade Names [Member]
Other Intangible Assets [Line Items]
Other intangible assets, non-amortizing	34,500	34,500	34,500
Other Intangible Assets [Rollforward]
Other intangible assets, non-amortizing, beginning balance	34,500	34,500
Additions from new business combinations, non-amortizing intangible assets		0
Transfers in (out), non-amortizing intangible assets		0
Measurement period adjustments, non-amortizing intangible assets		0
Currency translation adjustments, non-amortizing intangible assets		0
Other intangible assets, non-amortizing, ending balance		34,500
Pre-Qualifications [Member]
Other Intangible Assets [Line Items]
Other intangible assets, non-amortizing	72,900	0	$ 72,900
Other Intangible Assets [Rollforward]
Other intangible assets, non-amortizing, beginning balance	$ 72,900	72,900
Additions from new business combinations, non-amortizing intangible assets		0
Transfers in (out), non-amortizing intangible assets		(69,800)
Measurement period adjustments, non-amortizing intangible assets		0
Currency translation adjustments, non-amortizing intangible assets		(3,100)
Other intangible assets, non-amortizing, ending balance		$ 0

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets (Quarterly Assessment for Indicators of Impairment) (Narrative) (Details) $ in Thousands	3 Months Ended
	Sep. 30, 2020USD ($)reportingunit	Dec. 31, 2019USD ($)
Goodwill [Line Items]
Goodwill, net | $	$ 1,231,717	$ 1,221,440
Oil and Gas [Member]
Goodwill [Line Items]
Number of reporting units | reportingunit	3
Goodwill, net | $	$ 377,400
Oil and Gas [Member] | Reporting Unit A [Member]
Goodwill [Line Items]
Number of reporting units | reportingunit	1
Goodwill, net | $	$ 15,300
Reporting unit, percentage of fair value in excess of carrying amount	10.00%
Oil and Gas [Member] | Reporting Unit B [Member]
Goodwill [Line Items]
Number of reporting units | reportingunit	2

Goodwill and Other Intangible_7

Goodwill and Other Intangible Assets (2020 Acquisitions) (Narrative) (Details) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2020USD ($)yracquisition	Sep. 30, 2019USD ($)	Dec. 31, 2023USD ($)	Dec. 31, 2019acquisition
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition	4			6
Business combinations, cash, net of cash acquired	$ 11,251	$ 94,647
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high	$ 199,000
2020 Acquisitions [Member]
Business Acquisition [Line Items]
Business combinations, percentage of interests acquired	96.00%
Business combinations, cash, net of cash acquired	$ 9,800
Business combinations, contingent consideration, earn-out liabilities	7,200
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high	$ 13,000
2020 Acquisitions [Member] | Expected Term [Member] | Maximum [Member]
Business Acquisition [Line Items]
Business combinations, contingent consideration, earn-out period (in years) | yr	5
Forecast [Member] | 2020 Acquisitions [Member]
Business Acquisition [Line Items]
Business combinations, cash, net of cash acquired			$ 2,800
Communications and Electrical Transmission [Domain]
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition	2
Communications [Member]
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition	1			4
Electrical Transmission [Member]
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition	1

Goodwill and Other Intangible_8

Goodwill and Other Intangible Assets (2019 Acquisitions) (Narrative) (Details) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2020USD ($)acquisition	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)yracquisition
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition	4		6
Business combinations, cash, net of cash acquired	$ 11,251	$ 94,647
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, low	34,000
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high	199,000
2019 Acquisitions [Member]
Business Acquisition [Line Items]
Business combinations, percentage of interests acquired			96.00%
Business combinations, cash, net of cash acquired			$ 176,600
Business combinations, contingent consideration, earn-out liabilities			22,300
Business combinations, contingent consideration, mandatorily redeemable non-controlling interest			$ 17,800
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, low	2,000
Business combinations, contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high	$ 62,000
2019 Acquisitions [Member] | Expected Term [Member] | Minimum [Member]
Business Acquisition [Line Items]
Business combinations, contingent consideration, earn-out period (in years) | yr			3
2019 Acquisitions [Member] | Expected Term [Member] | Maximum [Member]
Business Acquisition [Line Items]
Business combinations, contingent consideration, earn-out period (in years) | yr			5
Oil and Gas [Member]
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition			1
Communications [Member]
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition	1		4
Clean Energy and Infrastructure [Member]
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition			1

Goodwill and Other Intangible_9

Goodwill and Other Intangible Assets (Pro Forma Financial Information and Acquisition Results) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Pro Forma Financial Information and Acquisition Results [Abstract]
Business combinations, unaudited supplemental pro forma revenue	$ 1,700	$ 2,100	$ 4,700	$ 5,800
Business combinations, unaudited supplemental pro forma net income (loss)	117.9	127.4	212.7	300.7
Business combinations, consolidated acquisition-related revenue	69.3	41.7	182.4	116.9
Business combinations, consolidated acquisition-related income (loss)	$ (4.3)	$ 1.5	$ (5)	$ (5.9)

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Acquisition-Related Contingent Consideration and Other Liabilities) (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, low	$ 34,000,000		$ 34,000,000
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high	$ 199,000,000		199,000,000
Acquisition-related contingent consideration liabilities, net increase (decrease), measurement period adjustments			$ 5,400,000
Discount Rate [Member] | Minimum [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, measurement input, discount rate	0.120		0.120
Discount Rate [Member] | Maximum [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, measurement input, discount rate	0.230		0.230
Discount Rate [Member] | Weighted Average [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, measurement input, discount rate	0.140		0.140
Earn-Out Liabilities [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, estimated fair value	$ 132,800,000		$ 132,800,000		$ 173,200,000
Acquisition-related contingent consideration liabilities, additions from new business combinations	0	$ 0	7,200,000	$ 16,200,000
Acquisition-related contingent consideration liabilities, net increase (decrease), measurement period adjustments	0	0	1,100,000	0
Acquisition-related contingent consideration liabilities, net increase (decrease), fair value adjustments, expense (income)	0	11,200,000	1,700,000	47,600,000
Acquisition-related contingent consideration liabilities, payments	0	$ 0	50,400,000	$ 30,000,000
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	$ 47,600,000		$ 47,600,000		$ 54,100,000

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Equity Investments) (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investments, adjusted cost basis, amount	$ 17,000,000		$ 18,000,000
Equity investments, carrying value	205,000,000		196,000,000
Equity investments, impairments	0	$ 0
Loans Receivable [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Financing commitments	$ 6,000,000
Waha JVs [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investment, ownership percentage	33.00%
Equity investments, carrying value	$ 165,000,000		$ 174,000,000
CCI [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investments, adjusted cost basis, amount	$ 15,000,000
FM Tech [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investment, ownership percentage	50.00%
Equity investments, carrying value	$ 16,000,000

Fair Value of Financial Instr_4

Fair Value of Financial Instruments (The Waha JVs) (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, equity in earnings (losses)	$ 7,445	$ 6,966	$ 22,092	$ 19,778
Equity method investments, net investment	205,000		205,000		$ 196,000
Unrealized gains (losses) on equity investee activity, net of tax	2,839	(7,108)	(21,447)	(21,302)
Waha JVs [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, equity in earnings (losses)	7,700	6,900	22,900	19,800
Equity method investments, cumulative undistributed earnings	60,700		60,700
Equity method investments, distributions of earnings received, operating cash flows	2,400	1,500	10,200	7,500
Equity method investments, net investment	165,000		165,000		$ 174,000
Unrealized gains (losses) on equity investee activity, before tax	2,500	(9,400)	(29,500)	(28,200)
Unrealized gains (losses) on equity investee activity, net of tax	$ 1,900	$ (7,100)	$ (22,400)	$ (21,300)

Fair Value of Financial Instr_5

Fair Value of Financial Instruments (Other Investments - AVCT) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Equity investments, adjusted cost basis, amount	$ 17	$ 17	$ 18
AVCT [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Equity investment ownership percentage	9.00%	9.00%	21.00%
Beneficial ownership of all interests, percentage	22.00%	22.00%	21.00%
Equity investment and warrants, amount paid (in dollars)	$ 5	$ 5
Unrealized fair value measurement gains, net, AVCT shares	0.9	4.7
Unrealized fair value measurement gains, AVCT convertible debentures	0.9	0.9
Equity investments, adjusted cost basis, amount			$ 2
AVCT [Member] | Common Stock [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Equity securities, fair value	$ 11	$ 11

Fair Value of Financial Instr_6

Fair Value of Financial Instruments (Other Investments - Telecommunications Entities) (Narrative) (Details) - Equity Investee [Member] - Subcontracting Arrangements [Member] $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2020USD ($)
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Payments or expenses, related party	$ 2.7	$ 9
Payables, related party	$ 0.4	$ 0.4

Fair Value of Financial Instr_7

Fair Value of Financial Instruments (Senior Notes) (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
4.875% Senior Notes [Member]
Fair Value Disclosure of Liabilities Not Measured at Fair Value [Line Items]
Senior Notes, gross carrying amount		$ 400
4.875% Senior Notes [Member] | Senior Notes [Member]
Fair Value Disclosure of Liabilities Not Measured at Fair Value [Line Items]
Debt instrument, interest rate (percentage)	4.875%
Debt instrument, maturity date	Mar. 15, 2023
Senior Notes, estimated fair value		$ 404.5
4.50% Senior Notes [Member]
Fair Value Disclosure of Liabilities Not Measured at Fair Value [Line Items]
Senior Notes, gross carrying amount	$ 600
4.50% Senior Notes [Member] | Senior Notes [Member]
Fair Value Disclosure of Liabilities Not Measured at Fair Value [Line Items]
Debt instrument, interest rate (percentage)	4.50%
Debt instrument, maturity date	Aug. 15, 2028
Senior Notes, estimated fair value	$ 606

Accounts Receivable, Net of A_3

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities (Schedule of Accounts Receivable, Net of Allowance and Contract Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Receivables [Abstract]
Contract billings	$ 939,600	$ 860,400
Less allowance	(22,500)	(10,100)
Accounts receivable, net of allowance	917,099	850,326
Contract Assets [Abstract]
Retainage	313,100	345,200
Unbilled receivables	706,800	679,400
Contract assets	$ 1,019,879	$ 1,024,568

Accounts Receivable, Net of A_4

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Provision for credit losses	$ 1,900	$ 400	$ 14,213	$ 1,326
Contract liabilities	368,184		368,184		$ 206,180
Contract with customer liability, deferred revenue current	349,100		349,100		$ 184,100
Deferred revenue, revenue recognized	10,300		139,600
Non-recourse financing agreement, discount charge	(13,553)	(19,297)	(45,365)	(58,178)
Receivables, Non-Recourse Arrangement [Member]
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Non-recourse financing agreement, discount charge	$ (900)	$ (2,400)	$ (4,100)	$ (8,100)
Minimum [Member]
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Retainage, percentage of contract billings			5.00%
Maximum [Member]
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Retainage, percentage of contract billings			10.00%

Property and Equipment, Net (Sc

Property and Equipment, Net (Schedule of Property and Equipment, Net) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property and Equipment [Line Items]
Property and equipment	$ 2,127,600	$ 1,923,500
Less accumulated depreciation and amortization	(1,133,400)	(1,017,700)
Property and equipment, net	994,193	905,835
Land [Member]
Property and Equipment [Line Items]
Property and equipment	6,000	4,900
Building and Leasehold Improvements [Member]
Property and Equipment [Line Items]
Property and equipment	40,800	35,800
Machinery and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment	1,834,700	1,659,400
Office Furniture and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment	216,300	197,300
Construction in Progress [Member]
Property and Equipment [Line Items]
Property and equipment	$ 29,800	$ 26,100

Property and Equipment, Net (Na

Property and Equipment, Net (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Capitalized internal-use software, gross	$ 149.3	$ 138.2
Capitalized internal-use software, net	$ 32.5	$ 31.5

Debt (Schedule of Carrying Valu

Debt (Schedule of Carrying Values of Debt) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Finance lease and other obligations	$ 300,200	$ 305,600
Total debt obligations	1,320,100	1,444,800
Less unamortized deferred financing costs	(16,700)	(12,400)
Total debt, net of deferred financing costs	1,303,400	1,432,400
Current portion of long-term debt	138,935	118,429
Long-term debt	$ 1,164,457	1,314,030
Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maturity date	Sep. 19, 2024
Credit Facility [Member] | Revolving Loans [Member]
Debt Instrument [Line Items]
Long-term debt obligations	$ 19,900	339,200
Credit Facility [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Long-term debt obligations	400,000	400,000
Senior Notes [Member] | 4.50% Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt obligations	$ 600,000	0
Debt instrument, interest rate (percentage)	4.50%
Debt instrument, maturity date	Aug. 15, 2028
Senior Notes [Member] | 4.875% Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt obligations	$ 0	$ 400,000
Debt instrument, interest rate (percentage)	4.875%
Debt instrument, maturity date	Mar. 15, 2023

Debt (Issuance of 4.50% Senior

Debt (Issuance of 4.50% Senior Notes and Repurchase and Redemption of 4.875% Senior Notes) (Details) - USD ($) $ in Thousands	Aug. 19, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Aug. 15, 2023	Aug. 15, 2028	Aug. 04, 2020
Debt Instrument [Line Items]
Repayments of 4.875% senior notes				$ 400,000	$ 0
Loss on extinguishment of debt		$ (5,569)	$ 0	$ (5,569)	$ 0
4.50% Senior Notes [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate (percentage)		4.50%		4.50%
Debt instrument, face amount								$ 600,000
Debt instrument, maturity date				Aug. 15, 2028
Debt issuance costs, gross		$ 8,900		$ 8,900
4.50% Senior Notes [Member] | Senior Notes [Member] | Forecast [Member]
Debt Instrument [Line Items]
Debt instrument, redemption price (percentage)						100.00%
Debt instrument, redemption price, percentage of principal amount redeemed						40.00%
Debt instrument redemption price percentage with equity offerings						104.50%
Debt instrument, change of control, redemption price, percent							101.00%
Debt instrument, minimum percentage of principal required to redeem in the event of default							30.00%
4.875% Senior Notes [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate (percentage)		4.875%		4.875%
Debt instrument, maturity date				Mar. 15, 2023
Repayments of 4.875% senior notes	$ 400,000
Debt instrument, redemption price (percentage)	100.813%
Loss on extinguishment of debt		$ 5,600
Payment for debt extinguishment, call premiums		3,300
Write off of deferred debt issuance cost		$ 2,300

Debt (Senior Secured Credit Fac

Debt (Senior Secured Credit Facility) (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Line of credit facility, letters of credit issued	$ 153	$ 115.1
Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	1,750
Line of credit facility, letters of credit issued	$ 134.8	$ 98
Line of credit facility, unused facility fee (percentage)	0.20%	0.20%
Credit Facility [Member] | Revolving Loans [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,350
Line of credit facility, remaining borrowing capacity	$ 1,195.3	$ 912.8
Credit Facility [Member] | Revolving Loans [Member] | Weighted Average [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	1.98%	3.50%
Credit Facility [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 400
Line of credit facility, interest rate (percentage)	1.39%	3.05%
Credit Facility [Member] | Term Loan [Member] | Forecast [Member]
Debt Instrument [Line Items]
Line of credit facility, term loan, amount of quarterly principal installment payments			$ 5	$ 2.5
Credit Facility [Member] | Foreign Denomination [Member]
Debt Instrument [Line Items]
Long-term line of credit	$ 20	$ 138
Line of credit facility, remaining borrowing capacity	280.1	162.4
Credit Facility [Member] | Letters of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, capacity available for letters of credit	$ 515.2	$ 552
Credit Facility [Member] | Letters of Credit [Member] | Performance Standby [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	0.375%	0.375%
Credit Facility [Member] | Letters of Credit [Member] | Commercial and/or Financial Standby [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	1.25%	1.25%

Debt (Other Credit Facilities)

Debt (Other Credit Facilities) (Narrative) (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Letters of credit issued	$ 153,000,000	$ 115,100,000
Other Credit Facilities [Member]
Debt Instrument [Line Items]
Long-term debt obligations	$ 5,100,000	0
Line of credit facility, interest rate (percentage)	3.20%
Line of Credit [Member] | Letters of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 50,000,000
Standby Letters of Credit [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Letters of credit issued	$ 18,200,000	$ 17,100,000
Standby Letters of Credit [Member] | Line of Credit [Member] | Letters of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	0.50%	0.40%

Debt (Additional Information) (

Debt (Additional Information) (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt instruments, accrued interest payable (in dollars)	$ 5.7	$ 7.5

Lease Obligations (Additional L

Lease Obligations (Additional Lease Information) (Narrative) (Details)	9 Months Ended
	Sep. 30, 2020
Lessee, Lease, Description [Line Items]
Finance leases, weighted average remaining lease term (in years)	2 years 6 months
Finance leases, weighted average discount rate, percent	4.00%
Operating leases, weighted average remaining lease term (in years)	4 years
Operating leases, weighted average discount rate, percent	3.90%
Minimum [Member] | Equipment Leases [Member]
Lessee, Lease, Description [Line Items]
Leases, renewal term	1 year
Minimum [Member] | Facility Leases [Member]
Lessee, Lease, Description [Line Items]
Leases, renewal term	1 year
Maximum [Member]
Lessee, Lease, Description [Line Items]
Leases, remaining lease terms	9 years
Maximum [Member] | Equipment Leases [Member]
Lessee, Lease, Description [Line Items]
Leases, renewal term	5 years
Maximum [Member] | Facility Leases [Member]
Lessee, Lease, Description [Line Items]
Leases, renewal term	5 years

Lease Obligations (Finance Leas

Lease Obligations (Finance Leases) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Leases [Abstract]
Finance leases, assets, gross	$ 536.8		$ 536.8		$ 463.5
Finance leases, assets, net	406.5		406.5		$ 375.9
Finance leases, assets, depreciation	$ 17.5	$ 13.1	$ 50.1	$ 34.2

Lease Obligations (Operating Le

Lease Obligations (Operating Leases) (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jan. 01, 2019
Operating Leased Assets [Line Items]
Operating leases, additions	$ 3,300	$ 19,900	$ 16,600	$ 86,400
Operating lease assets	187,531		187,531		$ 229,903
Operating leases, expense	25,600	29,500	87,700	84,800
Operating leases, variable lease costs	2,300	3,100	8,000	7,500
Operating leases, short-term leases, expense	$ 74,000	$ 144,000	$ 224,400	$ 352,400
Minimum [Member]
Operating Leased Assets [Line Items]
Operating leases, term of contract (in years)	1 year		1 year
Maximum [Member]
Operating Leased Assets [Line Items]
Operating leases, term of contract (in years)	1 year		1 year
Accounting Standards Update 2016-02 [Member]
Operating Leased Assets [Line Items]
Operating lease assets						$ 230,000

Lease Obligations (Schedule of

Lease Obligations (Schedule of Future Minimum Lease Commitments) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finance Leases
2020, remaining three months	$ 41,600
2021	131,700
2022	91,500
2023	38,900
2024	6,400
Thereafter	200
Total minimum lease payments	310,300
Less amounts representing interest	(15,200)
Total lease obligations, net of interest	295,100
Less current portion	128,900
Long-term portion of lease obligations, net of interest	166,200
Operating Leases
2020, remaining three months	29,400
2021	72,600
2022	46,500
2023	23,800
2024	15,600
Thereafter	30,000
Total minimum lease payments	217,900
Less amounts representing interest	(17,900)
Total lease obligations, net of interest	200,000
Less current portion	74,439	$ 81,561
Long-term portion of lease obligations, net of interest	$ 125,639	$ 154,553

Stock-Based Compensation and _3

Stock-Based Compensation and Other Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Stock-based compensation plans, number of shares available for future grant	3,011,000		3,011,000
Non-cash stock-based compensation expense	$ 5.6	$ 4.2	$ 15.5	$ 12.1
Stock-based compensation, income tax benefits	$ 1.4	$ 1	3.6	5.3
Stock-based compensation, vested awards, net income tax benefits (deficiencies)			$ (0.1)	$ 2.3

Stock-Based Compensation and _4

Stock-Based Compensation and Other Employee Benefit Plans (Restricted Shares) (Narrative) (Details) - Restricted Shares [Member] - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation awards, unearned compensation	$ 31	$ 31		$ 31
Stock-based compensation awards, unearned compensation, weighted average expected recognition period (in years)	2 years
Stock-based compensation, vested awards, intrinsic value		$ 0.2	$ 0.2	$ 6.7	$ 14.1

Stock-Based Compensation and _5

Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Activity, Restricted Shares) (Details)	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Restricted Shares [Member]
Restricted Shares
Non-vested restricted shares, beginning balance (in shares)	1,221,593
Granted (in shares)	936,946
Vested (in shares)	(183,885)
Canceled/forfeited (in shares)	(239,900)
Non-vested restricted shares, ending balance (in shares)	1,734,754
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	$ 45.36
Granted (in dollars per share) | $ / shares	27.15
Vested (in dollars per share) | $ / shares	39.60
Canceled/forfeited (in dollars per share) | $ / shares	58.96
Non-vested restricted shares, per share weighted average grant date fair value, ending balance (in dollars per share) | $ / shares	$ 34.26
Restricted Stock Units [Member]
Restricted Shares
Non-vested restricted shares, ending balance (in shares)	2,300

Stock-Based Compensation and _6

Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Employee Stock Purchase Plans) (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Cash proceeds (in dollars)	$ 5,483	$ 3,414
Common shares issued (in shares)	193,655	87,014
Weighted average price per share purchased under employee stock purchase plans	$ 28.29	$ 39.23
Weighted average per share grant date fair value (in dollars per share)	$ 8.61	$ 9.97
Employee Stock Purchase Plans [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Cash proceeds (in dollars)	$ 5,500	$ 3,400

Other Retirement Plans (Schedul

Other Retirement Plans (Schedule of Covered Employees and Contributions, Multiemployer Plans) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)numberOfEmployees	Sep. 30, 2019USD ($)numberOfEmployees	Sep. 30, 2020USD ($)numberOfEmployees	Sep. 30, 2019USD ($)numberOfEmployees
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer Plan, Employer Contribution, Cost	$ 8.9	$ 24.2	$ 25	$ 55.7
Pension Plan [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer Plan, Employer Contribution, Cost	7.2	23	19.5	51.7
Multiemployer Plans, Other Multiemployer [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer Plan, Employer Contribution, Cost	$ 1.7	$ 1.2	$ 5.5	$ 4
Low [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer plans, covered employees (in number of employees) | numberOfEmployees	1,452	3,814	1,119	1,626
High [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer plans, covered employees (in number of employees) | numberOfEmployees	1,469	5,349	1,469	5,349

Equity (Share Activity) (Narrat

Equity (Share Activity) (Narrative) (Details) - USD ($) shares in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Mar. 19, 2020	Dec. 21, 2018	Sep. 11, 2018
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)	3.6
Treasury stock acquired, value	$ 120,228,000	$ 602,000
Stock repurchase program, remaining authorized repurchase amount	$ 158,600,000
September 2018 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)	0.6
Treasury stock acquired, value	$ 28,800,000
Share repurchase program, amount authorized, value					$ 150,000,000
December 2018 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)	3
Treasury stock acquired, value	$ 91,400,000
Share repurchase program, amount authorized, value				$ 100,000,000
Stock repurchase program, remaining authorized repurchase amount	8,600,000
March 2020 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Share repurchase program, amount authorized, value			$ 150,000,000
Stock repurchase program, remaining authorized repurchase amount	$ 150,000,000

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Consolidated effective tax rate, percent	25.70%	25.00%	22.70%	24.50%
Effective income tax rate reconciliation, other adjustments, amount			$ 9.6
Stock-based compensation, vested awards, net tax benefits				$ 2.3

Segments and Related Informat_3

Segments and Related Information (Narrative) (Details)	9 Months Ended
	Sep. 30, 2020numberOfSegments
Segment Reporting [Abstract]
Number of operating segments	5
Number of reportable segments	5

Segments and Related Informat_4

Segments and Related Information (Schedule of Financial Information by Reportable Segment - Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue:
Revenue (in dollars)	$ 1,698,279	$ 2,016,618	$ 4,684,180	$ 5,473,965
Communications [Member] | Customer Concentration Risk [Member] | Revenue [Member] | Utilities [Member]
Revenue:
Utilities customers, percentage of Communications segment revenue	15.70%	14.90%	15.30%	15.30%
Reportable Segments [Member] | Communications [Member]
Revenue:
Revenue (in dollars)	$ 645,400	$ 679,500	$ 1,943,800	$ 1,944,900
Reportable Segments [Member] | Oil and Gas [Member]
Revenue:
Revenue (in dollars)	462,500	972,500	1,190,100	2,530,500
Reportable Segments [Member] | Electrical Transmission [Member]
Revenue:
Revenue (in dollars)	128,500	103,000	380,700	298,300
Reportable Segments [Member] | Clean Energy and Infrastructure [Member]
Revenue:
Revenue (in dollars)	468,900	261,700	1,181,400	701,300
Reportable Segments [Member] | Other [Member]
Revenue:
Revenue (in dollars)	100	100	200	100
Eliminations [Member]
Revenue:
Revenue (in dollars)	$ (7,100)	$ (200)	$ (12,000)	$ (1,100)

Segments and Related Informat_5

Segments and Related Information (Schedule of Financial Information by Reportable Segment - EBITDA) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
EBITDA:
EBITDA	$ 253.6	$ 247.9	$ 527.4	$ 620.8
Reportable Segments [Member] | Communications [Member]
EBITDA:
EBITDA	79.6	57.1	206.8	154.8
Reportable Segments [Member] | Oil and Gas [Member]
EBITDA:
EBITDA	160.4	212.9	315	499.6
Reportable Segments [Member] | Electrical Transmission [Member]
EBITDA:
EBITDA	9.1	7.8	14.2	20.3
Reportable Segments [Member] | Clean Energy and Infrastructure [Member]
EBITDA:
EBITDA	34.4	2.3	69.5	14.4
Reportable Segments [Member] | Other [Member]
EBITDA:
EBITDA	7.6	6.7	22.5	19.4
Corporate [Member]
EBITDA:
EBITDA	$ (37.5)	$ (38.9)	$ (100.6)	$ (87.7)

Segments and Related Informat_6

Segments and Related Information (Schedule of Financial Information by Reportable Segment - Depreciation and Amortization) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Depreciation and Amortization:
Depreciation and amortization	$ 82.6	$ 55.2	$ 210.6	$ 174.2
Reportable Segments [Member] | Communications [Member]
Depreciation and Amortization:
Depreciation and amortization	21.1	15.7	62.1	45.7
Reportable Segments [Member] | Oil and Gas [Member]
Depreciation and Amortization:
Depreciation and amortization	47.5	28.8	107.7	97.7
Reportable Segments [Member] | Electrical Transmission [Member]
Depreciation and Amortization:
Depreciation and amortization	6.2	5.1	18.6	14.8
Reportable Segments [Member] | Clean Energy and Infrastructure [Member]
Depreciation and Amortization:
Depreciation and amortization	5	3.3	13.7	9.7
Reportable Segments [Member] | Other [Member]
Depreciation and Amortization:
Depreciation and amortization	0	0	0	0.1
Corporate [Member]
Depreciation and Amortization:
Depreciation and amortization	$ 2.8	$ 2.3	$ 8.5	$ 6.2

Segments and Related Informat_7

Segments and Related Information (Reconciliation of Consolidated Income before Income Taxes to EBITDA) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
EBITDA Reconciliation:
Income before income taxes	$ 157,405	$ 173,385	$ 271,455	$ 388,484
Interest expense, net	13,553	19,297	45,365	58,178
Depreciation	71,397	50,515	182,173	160,019
Amortization of intangible assets	11,200	4,681	28,384	14,152
EBITDA	$ 253,600	$ 247,900	$ 527,400	$ 620,800

Segments and Related Informat_8

Segments and Related Information (Foreign Operations) (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segments and Related Information [Line Items]
Revenue			$ 1,698,279	$ 2,016,618	$ 4,684,180	$ 5,473,965
Property and equipment, net	$ 994,193	$ 905,835	994,193		994,193
United States [Member]
Segments and Related Information [Line Items]
Revenue			1,700,000	2,000,000	4,600,000	5,300,000
Property and equipment, net	971,400	874,700	971,400		971,400
Intangible assets and goodwill, net	1,400,000	1,400,000	1,400,000		1,400,000
Foreign Operations [Member]
Segments and Related Information [Line Items]
Revenue			18,200	$ 64,100	77,800	$ 191,000
Property and equipment, net	22,800	31,100	22,800		22,800
Intangible assets and goodwill, net	$ 50,300	$ 56,400	$ 50,300		$ 50,300
Foreign Operations [Member] | Accounts Receivable, Net, Less Deferred Revenue [Member] | Geographic Concentration Risk [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total	4.00%	5.00%
Govermment [Member] | Revenue Benchmark [Member] | Customer Concentration Risk [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total			2.00%	1.00%	2.00%	1.00%

Segments and Related Informat_9

Segments and Related Information Segments and Related Information (Significant Customers) (Narrative) (Details) - Revenue Benchmark [Member] - Customer Concentration Risk [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AT&T [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total	15.00%	18.00%	19.00%	20.00%
Equitrans Midstream Corporation/EQT Corporation [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total	3.00%	17.00%	2.00%	12.00%

Commitments and Contingencies (

Commitments and Contingencies (Legal, Letters of Credit, Bonds, Self-Insurance) (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Commitments and Contingencies [Line Items]
Letters of credit issued	$ 153	$ 115.1
Self-Insurance [Member] | Workers' Compensation, General and Automobile Policies [Member]
Commitments and Contingencies [Line Items]
Self-insurance reserve	129	123.4
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	85.9	87.3
Self-Insurance [Member] | Employee Group Medical Claims [Member]
Commitments and Contingencies [Line Items]
Self-insurance reserve	4.1	4.2
Performance and Payment Bonds [Member]
Commitments and Contingencies [Line Items]
Bonded projects, estimated costs to complete	226.3	194.7
Performance and Payment Bonds [Member] | Subsidiaries [Member]
Commitments and Contingencies [Line Items]
Outstanding bonds, amount	640.1	551.4
Financial Guarantees [Member] | Self-Insurance [Member] | Workers' Compensation, General and Automobile Policies [Member]
Commitments and Contingencies [Line Items]
Letters of credit issued	59.3	64
Surety Bonds [Member] | Self-Insurance [Member] | Workers' Compensation [Member]
Commitments and Contingencies [Line Items]
Outstanding bonds, amount	$ 37.4	$ 38.5

Commitments and Contingencies_2

Commitments and Contingencies (Investment Arrangements) (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Other Commitments [Line Items]
Cash	$ 238,174	$ 71,427
Proportionately Consolidated Non-Controlled Joint Venture [Member]
Other Commitments [Line Items]
Cash	$ 8,400	$ 13,100
Proportionately Consolidated Non-Controlled 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%
Proportionately Consolidated Non-Controlled 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%
Proportionately Consolidated Non-Controlled Joint Venture [Member] | Joint Venture Civil Construction Project [Member]
Other Commitments [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage	50.00%

Commitments and Contingencies_3

Commitments and Contingencies (Other Guarantees) (Narrative) (Details)	9 Months Ended
	Sep. 30, 2020
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

Commitments and Contingencies_4

Commitments and Contingencies (Concentrations of Risk) (Narrative) (Details) - numberOfCustomers	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Concentration Risk [Line Items]
Number of customers					435
Accounts Receivable, Net, Less Deferred Revenue [Member] | Credit Concentration Risk [Member] | Customers with Largest Net Accounts Receivable Positions [Member]
Concentration Risk [Line Items]
Number of customers	2	3
Accounts Receivable, Net, Less Deferred Revenue [Member] | Credit Concentration Risk [Member] | Customer with Largest Net Accounts Receivable Position [Member]
Concentration Risk [Line Items]
Concentration risk, percentage of total	15.00%	17.00%
Accounts Receivable, Net, Less Deferred Revenue [Member] | Credit Concentration Risk [Member] | Customer with Second Largest Net Accounts Receivable Position [Member]
Concentration Risk [Line Items]
Concentration risk, percentage of total	13.00%	13.00%
Accounts Receivable, Net, Less Deferred Revenue [Member] | Credit Concentration Risk [Member] | Customer with Third Largest Net Accounts Receivable Position [Member]
Concentration Risk [Line Items]
Concentration risk, percentage of total		11.00%
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			63.00%	65.00%	61.00%	63.00%

Related Party Transactions (Man

Related Party Transactions (Management) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Community Condotte DeMoya JV, LLC [Member]
Related Party Transaction [Line Items]
Equity method investment, ownership percentage	25.00%		25.00%
Negative equity method investment	$ (1.7)		$ (1.7)
Management [Member] | 2019 Acquisitions [Member]
Related Party Transaction [Line Items]
Payments for advance to affiliate			1.2
Advances outstanding, related party	0.6		0.6
Management [Member] | Equipment, Supplies and Services [Member]
Related Party Transaction [Line Items]
Payments, related party	23.8	$ 25.5	65.3	$ 71.8
Payables, related party	5.9		5.9		$ 14.7
Revenue, related party	0.9	0.7	3.2	1.6
Receivables, net, related party	0.5		0.5
Management [Member] | Subcontracting Arrangements [Member]
Related Party Transaction [Line Items]
Payments, related party	0	$ 3.1	0.6	$ 9.3
Payables, related party	0.1		0.1		$ 0.2
Management [Member] | Subcontracting Arrangements [Member] | 2019 Acquisitions [Member]
Related Party Transaction [Line Items]
Receivables, net, related party	0.2		0.2
Charges, related party	0.6		0.6
Management [Member] | Subcontracting Arrangements [Member] | Community Condotte DeMoya JV, LLC [Member]
Related Party Transaction [Line Items]
Receivables, net, related party	$ 2.2		$ 2.2

Related Party Transactions (Con

Related Party Transactions (Construction Management Firm and CCI) (Narrative) (Details) - Immediate Family Member of Management [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Construction Management Firm Specializing in Steel Building Systems [Member]
Related Party Transaction [Line Items]
Advances outstanding, related party					$ 0.5
CCI [Member]
Related Party Transaction [Line Items]
Equity investment, ownership percentage	15.00%		15.00%
CCI [Member] | Equipment [Member]
Related Party Transaction [Line Items]
Payments, net of rebates, related party	$ 1.8	$ 7.7	$ 3.2	$ 23.6
Payables, related party	1.6		1.6		$ 0.2
Revenue, related party	0.2		0.8
Receivables, related party	$ 0.2		$ 0.2

Related Party Transactions (Exe

Related Party Transactions (Executive Officers) (Narrative) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)numberOfEmployees	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)numberOfEmployees	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Management [Member] | Subcontracting Arrangements [Member]
Related Party Transaction [Line Items]
Number of management members, subcontracting arrangement | numberOfEmployees	2		2
Payments or expenses, related party	$ 0	$ 3.1	$ 0.6	$ 9.3
Payables, related party	0.1		0.1		$ 0.2
Chairman, Board of Directors [Member] | Lease Agreements [Member]
Related Party Transaction [Line Items]
Payments or expenses, related party	0.6	0.6	1.9	2
Executive Officers [Member] | Related Customer [Member]
Related Party Transaction [Line Items]
Receivables, related party	1		1		0.8
Charges, related party	0.3	0.3	1	1.1
Executive Officers [Member] | Construction Services [Member]
Related Party Transaction [Line Items]
Payments or expenses, related party			0.2
Revenue, related party	0.7	$ 5.2	6.2	$ 7.4
Receivables, related party	$ 0.7		$ 0.7		$ 3.9

Related Party Transactions (Spl

Related Party Transactions (Split Dollar Agreements) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Chairman, Board of Directors [Member]
Related Party Transaction [Line Items]
Payments for life insurance policies	$ 0.6	$ 0.6	$ 1.1	$ 1.1
Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Payments for life insurance policies	0	$ 0	0.7	$ 0.7
Executive Officers [Member]
Related Party Transaction [Line Items]
Life insurance assets, carrying amount	$ 22.2		$ 22.2		$ 20.3