MasTec (MTZ) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	May 03, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
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	2021
Document Fiscal Period Focus	Q1
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		74,311,342

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 1,775,424	$ 1,416,604
Costs of revenue, excluding depreciation and amortization	1,513,859	1,226,297
Depreciation	79,264	53,089
Amortization of intangible assets	11,247	7,391
General and administrative expenses	73,108	85,514
Interest expense, net	12,459	17,004
Equity in earnings of unconsolidated affiliates	(7,346)	(7,834)
Other income, net	(2,596)	(1,342)
Income before income taxes	95,429	36,485
Provision for income taxes	(29,317)	(423)
Net income	66,112	36,062
Net income (loss) attributable to non-controlling interests	463	(168)
Net income attributable to MasTec, Inc.	$ 65,649	$ 36,230
Earnings per share (Note 2):
Basic earnings per share (in dollars per share)	$ 0.91	$ 0.48
Basic weighted average common shares outstanding	72,439	74,738
Diluted earnings per share (in dollars per share)	$ 0.89	$ 0.48
Diluted weighted average common shares outstanding	73,846	75,413

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 66,112	$ 36,062
Other comprehensive income (loss):
Foreign currency translation gains (losses), net of tax	371	(296)
Unrealized gains (losses) on investment activity, net of tax	13,839	(22,961)
Comprehensive income	80,322	12,805
Comprehensive income (loss) attributable to non-controlling interests	463	(168)
Comprehensive income attributable to MasTec, Inc.	$ 79,859	$ 12,973

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 512,407	$ 423,118
Accounts receivable, net of allowance	876,715	784,488
Contract assets	958,064	969,743
Inventories, net	92,677	89,645
Prepaid expenses	59,825	60,631
Other current assets	50,736	31,390
Total current assets	2,550,424	2,359,015
Property and equipment, net	1,024,509	982,328
Operating lease assets	162,359	176,573
Goodwill, net	1,262,718	1,243,034
Other intangible assets, net	225,566	184,043
Other long-term assets	312,727	282,856
Total assets	5,538,303	5,227,849
Current liabilities:
Current portion of long-term debt, including finance leases	157,257	145,110
Current portion of operating lease liabilities	69,184	72,481
Accounts payable	632,088	571,269
Accrued salaries and wages	176,450	135,316
Other accrued expenses	236,753	187,647
Contract liabilities	259,488	228,388
Other current liabilities	101,680	74,988
Total current liabilities	1,632,900	1,415,199
Long-term debt, including finance leases	1,170,419	1,157,632
Long-term operating lease liabilities	106,971	116,506
Deferred income taxes	304,006	302,938
Other long-term liabilities	235,032	230,049
Total liabilities	3,449,328	3,222,324
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 - 93,253,268 and 93,107,440 (including 1,870,460 and 1,843,041 of unvested stock awards) as of March 31, 2021 and December 31, 2020, respectively	9,325	9,311
Capital surplus	840,567	837,453
Retained earnings	1,899,206	1,833,557
Accumulated other comprehensive loss	(77,234)	(91,444)
Treasury stock, at cost: 18,941,926 shares as of both March 31, 2021 and December 31, 2020, respectively	(586,955)	(586,955)
Total MasTec, Inc. shareholders’ equity	2,084,909	2,001,922
Non-controlling interests	4,066	3,603
Total equity	2,088,975	2,005,525
Total liabilities and equity	$ 5,538,303	$ 5,227,849
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	93,253,268	93,107,440
Treasury stock, shares	18,941,926	18,941,926
Common Stock [Member]
Equity
Total equity	$ 9,325	$ 9,311
Common stock, shares issued	93,253,268	93,107,440
Restricted Stock Awards [Member] | Common Stock [Member]
Unvested stock awards (in shares)	1,870,460	1,843,041

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, 2019		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)
Condensed Unaudited Consolidated Statements of Equity
Net income (loss)	36,062				36,230		36,230	(168)
Other comprehensive income (loss)	(23,257)					(23,257)	(23,257)
Non-cash stock-based compensation	4,049			4,049			4,049
Issuance of restricted shares, net (in shares)		694,779
Issuance of restricted shares, net	0	$ 69		(69)			0
Other stock issuances, net of shares withheld for taxes (in shares)		13,823
Other stock issuances, net of shares withheld for taxes	$ 694	$ 2		692			694
Acquisition of treasury stock, at cost (in shares)	(3,600,000)		(3,569,924)
Acquisition of treasury stock, at cost	$ (119,426)		$ (119,426)				(119,426)
Ending balance, common shares outstanding (in shares) at Mar. 31, 2020		92,618,032
Ending balance at Mar. 31, 2020	$ 1,689,813	$ 9,262	$ (586,153)	814,425	1,546,939	(98,963)	1,685,510	4,303
Ending balance, treasury shares (in shares) at Mar. 31, 2020			(18,914,841)
Beginning balance, common shares outstanding (in shares) at Dec. 31, 2020	93,107,440	93,107,440
Beginning balance at Dec. 31, 2020	$ 2,005,525	$ 9,311	$ (586,955)	837,453	1,833,557	(91,444)	2,001,922	3,603
Beginning balance, treasury shares (in shares) at Dec. 31, 2020	(18,941,926)		(18,941,926)
Condensed Unaudited Consolidated Statements of Equity
Net income (loss)	$ 66,112				65,649		65,649	463
Other comprehensive income (loss)	14,210					14,210	14,210
Non-cash stock-based compensation	5,528			5,528			5,528
Issuance of restricted shares, net (in shares)		138,081
Issuance of restricted shares, net	0	$ 14		(14)			0
Other stock issuances, net of shares withheld for taxes (in shares)		7,747
Other stock issuances, net of shares withheld for taxes	$ (2,400)	$ 0		(2,400)			(2,400)
Acquisition of treasury stock, at cost (in shares)	0
Ending balance, common shares outstanding (in shares) at Mar. 31, 2021	93,253,268	93,253,268
Ending balance at Mar. 31, 2021	$ 2,088,975	$ 9,325	$ (586,955)	$ 840,567	$ 1,899,206	$ (77,234)	$ 2,084,909	$ 4,066
Ending balance, treasury shares (in shares) at Mar. 31, 2021	(18,941,926)		(18,941,926)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 66,112	$ 36,062
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	79,264	53,089
Amortization of intangible assets	11,247	7,391
Non-cash interest expense, net	783	725
Non-cash stock-based compensation expense	5,528	4,049
Benefit from deferred income taxes	(19,838)	(12,614)
Equity in earnings of unconsolidated affiliates	(7,346)	(7,834)
Gains on sales of assets, net	(1,965)	(2,407)
Other non-cash items, net	(5,578)	734
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	(61,993)	48,337
Contract assets	26,799	26,311
Inventories	651	5,932
Other assets, current and long-term portion	(7,961)	17,906
Accounts payable and accrued expenses	153,386	34,058
Contract liabilities	14,782	2,603
Other liabilities, current and long-term portion	3,293	(11,076)
Net cash provided by operating activities	257,164	203,266
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired	(88,646)	0
Capital expenditures	(48,058)	(60,594)
Proceeds from sale of property and equipment	6,035	8,363
Payments for other investments	(4,350)	(12,000)
Proceeds from other investments	557	648
Other investing activities, net	(150)	4,843
Net cash used in investing activities	(134,612)	(58,740)
Cash flows from financing activities:
Proceeds from credit facilities	18,155	675,935
Repayments of credit facilities	(8,869)	(671,780)
Payments of finance lease obligations	(38,222)	(30,856)
Proceeds from stock-based awards	0	1,476
Payments for stock-based awards	(3,753)	(572)
Repurchases of common stock	0	(119,427)
Other financing activities, net	(502)	0
Net cash used in financing activities	(33,191)	(145,224)
Effect of currency translation on cash	(72)	934
Net increase in cash and cash equivalents	89,289	236
Cash and cash equivalents - beginning of period	423,118	71,427
Cash and cash equivalents - end of period	512,407	71,663
Supplemental cash flow information:
Interest paid	21,689	21,479
Supplemental disclosure of non-cash information:
Additions to property and equipment from finance leases	$ 50,772	$ 26,932

Business, Basis of Presentation

Business, Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
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; power generation, including from clean energy and renewable sources; pipeline infrastructure; electrical utility transmission and distribution; heavy civil; and industrial infrastructure. MasTec’s customers are primarily in these industries. MasTec reports its results under five reportable segments: (1) Communications; (2) Clean Energy and Infrastructure; (3) Oil and Gas; (4) Electrical Transmission; and (5) Other. See Note 13 - Segments and Related Information. 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, 2020 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, 2020 contained in the Company’s 2020 Annual Report on Form 10-K (the “2020 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 applies the equity method of accounting for its investments in entities for which it does not have a controlling financial interest, but over which it has the ability to exert significant influence. See Note 4 - Fair Value of Financial Instruments. 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. For foreign operations for which the local currency is not the functional currency, the operation’s non-monetary assets are remeasured into U.S. dollars at historical exchange rates. All other accounts are remeasured at current exchange rates. Gains or losses from remeasurement are included in other income or expense, net. 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 that management believes to be reasonable under the circumstances, including the potential future effects of the COVID-19 pandemic, climate change, and other relevant global and/or macroeconomic trends and 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 these 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 the first quarter of 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 disrupted business activities and significantly affected global economic conditions in 2020 and continuing into 2021 as federal, state and local governments imposed restrictions and mitigation measures to address the public health crisis, the effects of which resulted in workforce, supply chain and production disruptions and created significant uncertainties in the U.S. and global economies. While the adverse effects of these restrictions and mitigation measures partially subsided in the second half of 2020 and into 2021, the possibility of future restrictions remains in the event of a rise in the number of COVID-19 cases in the future. As a provider of essential services, all of the Company’s business segments continued to operate throughout 2020 and into 2021, and where safe and possible, the Company’s customers generally directed it to maintain normal work schedules. The Company’s business model has, thus far, proven resilient, and management continues to adapt to the changing operational and economic environment that has resulted from the COVID-19 pandemic. Management’s top priority has been to take appropriate actions to protect the health and safety of its employees, customers and business partners. The Company has adjusted its standard operating procedures within its business operations to ensure employee and customer safety, and is continually monitoring evolving health guidelines and responding to changes as appropriate. The COVID-19 pandemic had a negative impact on the Company’s operations in 2020 and is expected to continue to affect its business activities in 2021. These impacts include lost productivity from governmental permitting approval delays, reduced crew productivity due to social distancing, other mitigation measures and 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. Several relief measures have been enacted in response to the effects of the COVID-19 pandemic, including the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) and the Coronavirus Response and Relief Supplemental Appropriations Act (the “Coronavirus Relief Act”). The CARES Act permitted deferral and/or reduction of certain federal and payroll tax amounts, certain of which the Company pursued, including the deferral of approximately $59 million of payroll taxes, half of which are due by December 31, 2021, with the remainder due by December 31, 2022. The Company will continue to monitor and evaluate the potential effects, usefulness of, and qualification for, additional COVID-19 relief measures on the Company’s financial position, results of operations and cash flows. Notwithstanding moderation of the COVID-19 pandemic and easing of governmental and other restrictions, the Company may continue to experience negative effects on its business and operations from possible longer-term changes in consumer and customer behavior, and/or from continuing negative economic conditions. The Company believes that it has taken appropriate steps to mitigate the impacts of the COVID-19 pandemic on its business; however, the potential effects of the COVID-19 pandemic are uncertain, as they depend upon numerous evolving factors that management may not be able to accurately predict. The availability of effective treatments and vaccines, the speed with which they can be administered to the public, the degree to which the public is willing to be vaccinated and the degree that vaccines are effective in preventing infection or illness from existing or new strains of COVID-19, along with the length and extent of any continuing economic and market disruptions are unknown, and, therefore, any future impacts on our business, financial condition and/or results of operations 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 28% and 42% of consolidated revenue for the three month periods ended March 31, 2021 and 2020, 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 5% and 6% of consolidated revenue for the three month periods ended March 31, 2021 and 2020, respectively. 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 three month periods ended March 31, 2021 and 2020, 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, 2020 and 2019. Revenue recognized for the three month periods ended March 31, 2021 and 2020 as a result of changes in total contract transaction price estimates, including from variable consideration, from performance obligations satisfied or partially satisfied in prior periods, totaled approximately $13.8 million and $17.8 million, 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 $3.7 million and $5.5 million as of March 31, 2021 and December 31, 2020. 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 March 31, 2021, the amount of the Company’s remaining performance obligations was $5.0 billion. Based on current expectations, the Company expects to recognize approximately $4.0 billion of its remaining performance obligations as revenue during 2021, with the majority of the remaining balance to be recognized in 2022. 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 March 31, 2021 and December 31, 2020, the Company included approximately $59 million and $51 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 March 31, 2021 and December 31, 2020, these change orders and/or claims related to projects across the Company’s 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 The discussion below describes the effects of recent accounting pronouncements, as updated from the discussion in the Company’s 2020 Form 10-K. Accounting Pronouncements Adopted in 2021 In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which eliminates certain exceptions to the existing guidance for income taxes related to the approach for intra-period tax allocations, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. This ASU also simplifies the accounting for income taxes by clarifying and amending existing guidance related to the effects of enacted changes in tax laws or rates in the effective tax rate computation, the recognition of franchise tax and the evaluation of a step-up in the tax basis of goodwill, among other clarifications. ASU 2019-12, which the Company adopted during the first quarter of 2021, did not have a material effect on the Company’s consolidated financial statements.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Earnings Per Share	Note 2 – Earnings Per Share Basic earnings 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 March 31, 2021 2020 Net income attributable to MasTec: Net income - basic and diluted (a) $ 65,649 $ 36,230 Weighted average shares outstanding: Weighted average shares outstanding - basic 72,439 74,738 Dilutive common stock equivalents (b) 1,407 675 Weighted average shares outstanding - diluted 73,846 75,413 (a) Calculated as total net income less amounts attributable to non-controlling interests. (b) For the three month period ended March 31, 2021, there were 22,527 anti-dilutive common stock equivalents.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021 (in millions): Communications Clean Energy and Infrastructure Oil and Gas Electrical Total Goodwill Goodwill, gross $ 561.9 $ 166.4 $ 509.7 $ 150.1 $ 1,388.1 Accumulated impairment loss — — (125.4) — (125.4) Goodwill, net $ 561.9 $ 166.4 $ 384.3 $ 150.1 $ 1,262.7 For the three month period ended March 31, 2021, goodwill included additions of $19.7 million from new business combinations and a decrease of $0.2 million from measurement period adjustments. Currency translation effects related to goodwill and accumulated impairment losses for the three month period ended March 31, 2021 totaled approximately $1.8 million of gains and $1.6 million of losses, 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 Customer Relationships and Backlog Pre-Qualifications Other (a) Total Other intangible assets, gross, as of December 31, 2020 $ 34.5 $ 297.9 $ 73.8 $ 26.4 $ 432.6 Accumulated amortization (218.5) (10.6) (19.5) (248.6) Other intangible assets, net, as of December 31, 2020 $ 34.5 $ 79.4 $ 63.2 $ 6.9 $ 184.0 Additions from new business combinations — 48.0 — 4.3 52.3 Currency translation adjustments — — 0.5 — 0.5 Amortization expense (7.9) (2.7) (0.6) (11.2) Other intangible assets, net, as of March 31, 2021 $ 34.5 $ 119.5 $ 61.0 $ 10.6 $ 225.6 (a) Consists principally of trade names and non-compete agreements. Quarterly Assessment for Indicators of Impairment . During the first quarter of 2021, in conjunction with the Company’s quarterly review for indicators of impairment, management performed a quantitative assessment of the goodwill associated with one reporting unit within the Oil and Gas segment. Based on the results of this assessment, management determined that the estimated fair value of the reporting unit substantially exceeded its carrying value. 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 impairment charges to goodwill and indefinite-lived intangible assets in the future. Recent Acquisitions The Company seeks to grow and diversify its business both organically and through acquisitions and/or other strategic arrangements in order to deepen its market presence, broaden its geographic reach and expand its service offerings. 2021 Acquisitions. For the three month period ended March 31, 2021, MasTec completed two acquisitions, including all of the equity interests in a heavy civil infrastructure construction company that is included within the Company’s Clean Energy and Infrastructure segment, and all of the equity interests in a pipeline integrity and gas distribution contractor that is included within the Company’s Oil and Gas segment. The aggregate purchase price for these entities was composed of approximately $90 million in cash, net of cash acquired . Determination of the estimated fair values of net assets acquired for these acquisitions was preliminary as of March 31, 2021; as a result, further adjustments to these estimates may occur. 2020 Acquisitions. During the year ended December 31, 2020, MasTec completed five acquisitions. These acquisitions included the equity interests of two entities. Through a 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. As of the date of acquisition, the Company’s ownership interest in the consolidated subsidiary was 96%, and as of both March 31, 2021 and December 31, 2020, was 91%, with the non-controlling interests owned by members of subsidiary management. 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. Additionally, the Company acquired the assets of three entities in 2020, one that specializes in wireless telecommunications and one that specializes in install-to-the-home services, both of which are included within the Company’s Communications segment, and one that specializes in electrical transmission services that is included within the Company’s Electrical Transmission segment. The aggregate purchase price for these entities was composed of approximately $23.5 million in cash, net of cash acquired, with an additional $3.2 million due through 2023, subject to certain indemnification provisions, and earn-out liabilities with five-year terms valued at approximately $8.3 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 March 31, 2021, the range of remaining potential undiscounted earn-out liabilities for the 2020 acquisitions was estimated to be between $1 million and $13 million; however, there is no maximum payment amount. Determination of the estimated fair values of net assets acquired and earn-out liabilities for these acquisitions was preliminary as of March 31, 2021; as a result, further adjustments to these estimates may occur. Pro Forma Financial Information and Acquisition Results. For the three month periods ended March 31, 2021 and 2020, unaudited supplemental pro forma revenue totaled approximately $1.8 billion and $1.6 billion, respectively, and unaudited supplemental pro forma net income totaled approximately $68.6 million and $46.7 million, respectively. For the three month periods ended March 31, 2021 and 2020, the Company’s consolidated results of operations included acquisition-related revenue of approximately $86.8 million and $49.5 million, respectively, and included acquisition-related net income of approximately $1.2 million and acquisition-related net losses of approximately $1.2 million, respectively, based on the Company’s consolidated effective tax rates. These acquisition-related results include amortization of intangible assets and exclude the effects of acquisition costs and interest expense associated with consideration paid for the related acquisitions. Q2 2021 Acquisitions. In the second quarter of 2021, MasTec completed the acquisition of INTREN, LLC (“INTREN”), a premier specialty utility contractor primarily providing electrical distribution network services under various multi-year master services agreements to the nation’s largest utilities, municipalities and cooperatives. This entity will be included within the Company’s Electrical Transmission segment. MasTec acquired all of INTREN’s equity interests for approximately $420 million in cash plus an Earn-out, which is contingent upon INTREN’s results for the year ended December 31, 2021. The acquisition of INTREN was funded with cash on hand and borrowings under the Company’s senior secured credit facility and is subject to customary purchase price adjustments. MasTec also completed two additional immaterial acquisitions, which included all of the equity interests of a telecommunications and utility engineering services company and a heavy industrial general contractor that will be included within our Communications and Clean Energy and Infrastructure segments, respectively. Due to the limited amount of time since these acquisitions, the initial purchase accounting is incomplete. The Company will complete an initial allocation of purchase price to total net assets acquired for these acquisitions in the second quarter of 2021.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2021
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, convertible debentures 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, including for mandatorily redeemable non-controlling interests (together, “Earn-outs”), that are contingent upon the acquired business achieving certain levels of earnings in the future. As of March 31, 2021 and December 31, 2020, the estimated fair value of the Company’s Earn-out liabilities totaled $134.8 million and $135.2 million, respectively, of which $47.9 million and $48.1 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 March 31, 2021, ranged from 12.0% to 20.0%, with a weighted average rate of 13.1% 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 March 31, 2021, the range of potential undiscounted Earn-out liabilities was estimated to be between $56 million and $174 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. There were no Earn-out additions from new business combinations in either of the three month periods ended March 31, 2021 or 2020. For the three month period ended March 31, 2021, there were no measurement period adjustments, and for the three month period ended March 31, 2020, measurement period adjustments totaled an increase of approximately $1.1 million and related to a business in the Company’s Communications segment. Fair value adjustments across multiple segments totaled a net decrease of approximately $0.4 million for the three month period ended March 31, 2021, and totaled a net increase of approximately $1.8 million for the three month period ended March 31, 2020. There were no Earn-out payments in either of the three month periods ended March 31, 2021 or 2020. Equity Investments The Company’s equity investments as of March 31, 2021 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”); (ii) a 15% equity interest 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”; (iv) the Company’s equity interests in American Virtual Cloud Technologies, Inc., or “AVCT”; (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. Some of these investment or strategic arrangements may involve the extension of loans or other types of financing, including approximately $3 million of financing receivables as of both March 31, 2021 and December 31, 2020, and $3 million of financing commitments as of December 31, 2020. The Company has determined that certain of its investment arrangements are variable interest entities (“VIEs”). As of March 31, 2021, 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 March 31, 2021 and December 31, 2020, the aggregate carrying value of the Company’s equity investments, including equity investments measured on an adjusted cost basis, totaled approximately $242 million and $220 million, respectively. As of March 31, 2021 and December 31, 2020, equity investments measured on an adjusted cost basis, including the Company’s $15 million investment in CCI, totaled approximately $18 million and $17 million, respectively. There were no material changes in the fair values of, or impairments related to, these investments during either of the three month periods ended March 31, 2021 or 2020. The Waha JVs. The Waha JVs own and operate certain pipeline infrastructure that transports natural gas to the Mexican border for export. The Company’s investments in the Waha JVs are accounted for as equity method investments. 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 $7.6 million for the three month periods ended March 31, 2021 and 2020, respectively. Distributions of earnings from the Waha JVs are included within operating cash flows. There were no distributions of earnings for the three month period ended March 31, 2021, and for the three month period ended March 31, 2020, distributions of earnings totaled $2.6 million. Cumulative undistributed earnings from the Waha JVs, which represents cumulative equity in earnings for the Waha JVs less distributions of earnings, totaled $75.0 million as of March 31, 2021. 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 equity method goodwill associated with capitalized investment costs, totaled approximately $196 million and $175 million as of March 31, 2021 and December 31, 2020, 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 (the “Waha JV 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 month period ended March 31, 2021, the Company’s proportionate share of unrecognized unrealized activity on the Waha JV swaps totaled gains of approximately $17.3 million, or $13.1 million, net of tax, and for the three month period ended March 31, 2020, totaled losses of approximately $30.3 million, or $23.0 million, net of tax. 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 both March 31, 2021 and December 31, 2020, the Company’s ownership interest in AVCT’s common stock, represented by the AVCT shares, totaled approximately 9%, 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% as of March 31, 2021 and December 31, 2020, respectively. José R. Mas, MasTec’s Chief Executive Officer, was a director of AVCT 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 through 2025 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 both March 31, 2021 and December 31, 2020, the aggregate fair value of the Company’s investments in AVCT approximated $17 million. For the three month period ended March 31, 2021, the Company recorded unrealized fair value measurement losses, net, on the AVCT securities within other expense totaling approximately $1.0 million, 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 as determined based on Monte Carlo simulations, a Level 3 input, which were recognized within other comprehensive income, totaled approximately $1.0 million, or $0.8 million, net of tax, respectively, for the three month period ended March 31, 2021. There were no material changes in the fair value of the Company’s investment in AVCT for the three month period ended March 31, 2020. During the first quarter of 2021, MasTec committed to fund up to $2.5 million for a 75% equity interest in Confluence Networks, LLC (“Confluence”), an undersea fiber-optic communications systems developer and VIE, of which $0.4 million was funded during the three month period ended March 31, 2021. As of March 31, 2021, MasTec had less than a majority of the members on the board and determined that it did not have a controlling financial interest. The Company has the ability to exert significant influence over the VIE, and, as a result, the Company’s investment in Confluence was accounted for as an equity method investment as of March 31, 2021. The Company has equity interests in certain telecommunications entities that are accounted for as equity method investments, for which the Company had an aggregate investment of $21 million and $19 million, respectively, including $17 million and $16 million, respectively, for FM Tech, as of March 31, 2021 and December 31, 2020. The initial investment in FM Tech provided for an additional $9 million of purchase price upon resolution of certain contingencies, of which $2 million was paid in the first quarter of 2021. As of March 31, 2021, approximately $3 million of contingent payment liabilities were included within other current liabilities. For the three month period ended March 31, 2021, the Company made equity contributions of approximately $2 million related to these entities, and for the three month period ended March 31, 2020, the Company made no equity contributions. Certain of these entities provide services to MasTec. For the three month periods ended March 31, 2021 and 2020, expense recognized in connection with services provided by these entities totaled $1.8 million and $2.7 million, respectively, and related amounts payable totaled $0.3 million and $0.2 million as of March 31, 2021 and December 31, 2020, respectively. In addition, the Company has an employee leasing arrangement with one of these entities. Charges to this entity were de minimis for the three month period ended March 31, 2021, and related amounts receivable totaled $0.5 million and $0.4 million as of March 31, 2021 and December 31, 2020, respectively. Amounts advanced to these entities totaled $0.2 million for the three month period ended March 31, 2021, which amount was outstanding as of March 31, 2021. Senior Notes As of both March 31, 2021 and December 31, 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, as determined based on an exit price approach using Level 1 inputs, totaled $618.0 million and $625.5 million, respectively.

Accounts Receivable, Net of All

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities	3 Months Ended
	Mar. 31, 2021
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): March 31, December 31, Contract billings $ 889.5 $ 805.0 Less allowance (12.8) (20.5) Accounts receivable, net of allowance $ 876.7 $ 784.5 Retainage 314.0 287.7 Unbilled receivables 644.1 682.0 Contract assets $ 958.1 $ 969.7 Contract billings represent the amount of performance obligations that have been billed but have not yet been collected. 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 month period ended March 31, 2021, provisions for credit losses totaled a recovery of $7.7 million, resulting from successful collection efforts for previously reserved amounts. For the three month period ended March 31, 2020, provisions for credit losses totaled $1.6 million. 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 $259.5 million and $228.4 million as of March 31, 2021 and December 31, 2020, respectively, of which deferred revenue comprised approximately $240.8 million and $203.0 million, respectively. For the three month periods ended March 31, 2021 and 2020, the Company recognized revenue of approximately $146.8 million and $105.6 million, respectively, related to amounts that were included in deferred revenue as of December 31, 2020 and 2019, respectively, resulting primarily from the advancement of physical progress on the related projects during the related periods. The Company is party to non-recourse financing arrangements in the ordinary course of business, under which certain receivables are settled with the customer’s bank in return for a nominal fee. Discount charges related to these arrangements, which are included within interest expense, net, totaled approximately $0.8 million and $1.8 million for the three month periods ended March 31, 2021 and 2020, respectively.

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2021
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): March 31, December 31, Land $ 8.4 $ 6.0 Buildings and leasehold improvements 43.7 40.5 Machinery and equipment 1,972.1 1,875.5 Office furniture and equipment 228.3 221.6 Construction in progress 23.0 26.1 Total property and equipment $ 2,275.5 $ 2,169.7 Less accumulated depreciation and amortization (1,251.0) (1,187.4) Property and equipment, net $ 1,024.5 $ 982.3

Debt

Debt	3 Months Ended
	Mar. 31, 2021
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 March 31, December 31, Senior secured credit facility: September 19, 2024 Revolving loans $ 45.0 $ 32.7 Term loan 395.0 397.5 4.50% Senior Notes August 15, 2028 600.0 600.0 Finance lease and other obligations 302.9 288.5 Total debt obligations $ 1,342.9 $ 1,318.7 Less unamortized deferred financing costs (15.2) (16.0) Total debt, net of deferred financing costs $ 1,327.7 $ 1,302.7 Current portion of long-term debt 157.3 145.1 Long-term debt $ 1,170.4 $ 1,157.6 Senior Secured Credit Facility The Company’s senior secured credit facility (the “Credit Facility”) has aggregate borrowing commitments totaling approximately $1.75 billion, which amount is composed of $1.35 billion of revolving commitments and a term loan in the aggregate principal amount of $400 million. The term loan is subject to amortization in quarterly principal installments of $2.5 million, which commenced in December 2020. This 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 March 31, 2021 and December 31, 2020, outstanding revolving loans, which included $45 million and $33 million, respectively, of borrowings denominated in foreign currencies, accrued interest at weighted average rates of approximately 1.77% and 1.87% per annum, respectively. The term loan accrued interest at rates of 1.36% and 1.40% as of March 31, 2021 and December 31, 2020, respectively. Letters of credit of approximately $127.0 million and $133.6 million were issued as of March 31, 2021 and December 31, 2020, respectively. As of both March 31, 2021 and December 31, 2020, 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 both March 31, 2021 and December 31, 2020, availability for revolving loans totaled $1.2 billion, or up to $523.0 million and $516.4 million, respectively, for new letters of credit. Revolving loan borrowing capacity included $255.0 million and $267.3 million of availability in either Canadian dollars or Mexican pesos as of March 31, 2021 and December 31, 2020, respectively. The unused facility fee as of both March 31, 2021 and December 31, 2020 accrued at 0.20% per annum. The Credit Facility is guaranteed by certain subsidiaries of the Company (the “Guarantor Subsidiaries”) and 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. There were no outstanding borrowings under the Company’s other credit facilities as of either March 31, 2021 or December 31, 2020. Additionally, the Company has a separate credit facility, under which it may issue up to $50.0 million of performance standby letters of credit. As of March 31, 2021 and December 31, 2020, letters of credit issued under this facility totaled $26.2 million and $18.2 million, respectively, and accrued fees at 0.40% and 0.50% per annum, respectively. The Company’s other credit facilities are subject to customary provisions and covenants. Debt Guarantees and Covenants 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. MasTec was in compliance with the provisions and covenants of its outstanding debt instruments as of both March 31, 2021 and December 31, 2020. Additional Information As of March 31, 2021 and December 31, 2020, accrued interest payable, which is recorded within other accrued expenses in the consolidated balance sheets, totaled $4.8 million and $12.4 million, respectively. For additional information pertaining to the Company’s debt instruments, see Note 7 - Debt in the Company’s 2020 Form 10-K.

Lease Obligations

Lease Obligations	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021, the Company’s leases have remaining lease terms of up to eight 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 March 31, 2021 and December 31, 2020 totaled $591.3 million and $563.0 million, respectively. Assets held under finance leases, net of accumulated depreciation, totaled $439.1 million and $418.7 million as of March 31, 2021 and December 31, 2020, respectively. Depreciation expense associated with finance leases totaled $19.0 million and $15.8 million for the three month periods ended March 31, 2021 and 2020, respectively. Operating Leases Operating lease additions for the three month periods ended March 31, 2021 and 2020 totaled $5.5 million and $5.8 million, respectively. For the three month periods ended March 31, 2021 and 2020, rent expense for leases that have terms in excess of one year totaled approximately $27.4 million and $35.3 million, respectively, of which $2.2 million and $2.9 million, respectively, represented variable lease costs. The Company also incurred rent expense for leases with terms of one year or less totaling approximately $110.1 million and $77.5 million for the three month periods ended March 31, 2021 and 2020, 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 March 31, 2021 were as follows (in millions): Finance Leases Operating 2021, remaining nine months $ 115.4 $ 63.1 2022 115.3 51.5 2023 61.7 27.3 2024 22.5 17.3 2025 2.1 10.8 Thereafter — 19.8 Total minimum lease payments $ 317.0 $ 189.8 Less amounts representing interest (14.2) (13.6) Total lease obligations, net of interest $ 302.8 $ 176.2 Less current portion 142.2 69.2 Long-term portion of lease obligations, net of interest $ 160.6 $ 107.0

Stock-Based Compensation and Ot

Stock-Based Compensation and Other Employee Benefit Plans	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021, there were approximately 2,519,000 shares available for future grant. Non-cash stock-based compensation expense under all plans totaled $5.5 million and $4.0 million for the three month periods ended March 31, 2021 and 2020, respectively. Income tax benefits associated with stock-based compensation arrangements totaled $1.1 million and $0.9 million for the three month periods ended March 31, 2021 and 2020, respectively, including net tax benefits related to the vesting of share-based payment awards totaling $0.1 million and net tax deficiencies totaling $0.1 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 March 31, 2021, total unearned compensation related to restricted shares was approximately $45.7 million, which is expected to be recognized over a weighted average period of approximately 2.2 years. The fair value of restricted shares that vested, which is based on the market price on the date of vesting, totaled $10.9 million and $5.6 million for the three month periods ended March 31, 2021 and 2020, respectively. Activity, restricted shares: (a) Restricted Per Share Weighted Average Grant Date Fair Value Non-vested restricted shares, as of December 31, 2020 1,845,341 $ 34.90 Granted 146,681 92.29 Vested (110,662) 51.44 Canceled/forfeited (8,400) 29.80 Non-vested restricted shares, as of March 31, 2021 1,872,960 $ 38.44 (a) Includes 2,500 and 2,300 restricted stock units as of March 31, 2021 and December 31, 2020, respectively. Employee Stock Purchase Plans The Company has certain employee stock purchase plans (collectively, “ESPPs”), under which shares of the Company’s common stock are available for purchase by eligible participants. Effective January 1, 2021, the Company’s ESPPs were amended (the “Amended ESPPs”), eliminating the look-back option and changing the offering period from three months to two weeks. Under the Amended ESPPs, eligible participants are permitted to purchase MasTec, Inc. common stock at 85% of the fair market value of the shares on the date of purchase, which occurs on the last trading day of each two week offering period. Previously, these plans allowed participants to purchase MasTec, Inc. common stock at 85% of the fair market value of the shares at the lower of (i) the date of commencement of the offering period or (ii) the last day of the offering period, as defined in the plan documents. Prior to January 1, 2021, the fair value of purchases under the ESPPs was estimated using the Black-Scholes option-pricing valuation model. The Company may issue common shares to plan participants or reacquire common shares on the open market or in privately negotiated transactions, at the Company’s discretion. For the three month period ended March 31, 2021, 18,843 shares were purchased by employees for $1.4 million pursuant to the Amended ESPPs, which shares were reacquired by the Company on the open market. For the three month period ended March 31, 2020, 53,399 shares were purchased by employees for $1.5 million, which shares were newly issued by the Company. Compensation expense associated with the Company’s ESPPs totaled approximately $0.3 million and $0.4 million for the three month periods ended March 31, 2021 and 2020, respectively.

Other Retirement Plans

Other Retirement Plans	3 Months Ended
	Mar. 31, 2021
Retirement Benefits [Abstract]
Other Retirement Plans	Note 10 – Other Retirement Plans Multiemployer Plans. Certain of MasTec’s subsidiaries contribute amounts to multiemployer pension and other multiemployer benefit plans and trusts (“MEPPs”). 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 March 31: 2021 2,412 2,532 $ 22.5 $ 2.2 $ 24.7 2020 1,119 1,424 $ 5.4 $ 1.7 $ 7.1 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	3 Months Ended
	Mar. 31, 2021
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. There were no share repurchases under the Company’s share repurchase programs for the three month period ended March 31, 2021. For the three month period ended March 31, 2020, the Company repurchased 3.6 million shares of its common stock for an aggregate purchase price totaling approximately $119.4 million, of which 0.6 million shares were repurchased for $28.8 million under a $150 million share repurchase program that was completed in the first quarter of 2020, and 3.0 million shares of which were repurchased for $90.6 million under the Company’s December 2018 $100 million share repurchase program. As of March 31, 2021, $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. Accumulated Other Comprehensive Loss Unrealized foreign currency translation activity, net, for the three month periods ended March 31, 2021 and 2020 relates to the Company’s operations in Canada and Mexico. For the three month period ended March 31, 2021, unrealized investment activity includes unrealized gains on both the interest rate swaps associated with the Waha JVs and on the Company’s investment in AVCT convertible debentures. For the three month period ended March 31, 2020, unrealized losses on investment activity relates to the Waha JV swaps. See Note 4 - Fair Value of Financial Instruments for additional information pertaining to the Waha JV swaps and AVCT convertible debentures.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Note 12 – Income Taxes In determining the quarterly provision for income taxes, management uses an estimated annual effective tax rate based on forecasted annual pre-tax income, permanent tax differences, statutory tax rates and tax planning opportunities in the various jurisdictions in which the Company operates. The effect of significant discrete items is separately recognized in the quarter(s) in which they occur. For the three month periods ended March 31, 2021 and 2020, the Company’s consolidated effective tax rates were 30.7% and 1.2%, respectively. The Company’s effective tax rate for the three month period ended March 31, 2021 included the effect of $2.3 million related to non-deductible share-based compensation, and for the three month period ended March 31, 2020, benefited from the release of approximately $9.6 million of certain valuation allowances on Canadian deferred tax assets that were no longer necessary.

Segments and Related Informatio

Segments and Related Information	3 Months Ended
	Mar. 31, 2021
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) Clean Energy and Infrastructure; (3) Oil and Gas; (4) Electrical Transmission 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, as well as infrastructure for utilities, among others. The Clean Energy and Infrastructure segment primarily serves energy, utility and other end-markets through the installation and construction of power generation facilities, including from clean energy and renewable sources, such as wind, solar and biomass, as well as various types of heavy civil and industrial infrastructure. The Company performs engineering, construction and maintenance services for 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 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 March 31, Revenue: 2021 2020 Communications (a) $ 568.6 $ 644.1 Clean Energy and Infrastructure 350.4 286.3 Oil and Gas 725.5 359.1 Electrical Transmission 133.5 128.1 Other 0.0 0.0 Eliminations (2.6) (1.0) Consolidated revenue $ 1,775.4 $ 1,416.6 (a) Revenue generated primarily by utilities customers represented 20.1% and 15.2% of Communications segment revenue for the three month periods ended March 31, 2021 and 2020, respectively. For the Three Months Ended March 31, EBITDA: 2021 2020 Communications $ 48.9 $ 50.8 Clean Energy and Infrastructure 10.9 5.0 Oil and Gas 167.6 74.4 Electrical Transmission 3.6 8.3 Other 7.4 7.4 Corporate (40.0) (31.9) Consolidated EBITDA $ 198.4 $ 114.0 For the Three Months Ended March 31, Depreciation and Amortization: 2021 2020 Communications $ 21.8 $ 19.7 Clean Energy and Infrastructure 7.6 4.0 Oil and Gas 52.1 28.1 Electrical Transmission 6.1 5.9 Other 0.0 0.0 Corporate 2.9 2.8 Consolidated depreciation and amortization $ 90.5 $ 60.5 For the Three Months Ended March 31, EBITDA Reconciliation: 2021 2020 Income before income taxes $ 95.4 $ 36.5 Plus: Interest expense, net 12.5 17.0 Depreciation 79.3 53.1 Amortization of intangible assets 11.2 7.4 Consolidated EBITDA $ 198.4 $ 114.0 Foreign Operations and Other. MasTec has operations in North America, primarily in the United States and Canada, and, to a lesser extent, in Mexico, the Caribbean and India. Revenue derived from U.S. operations totaled $1.7 billion and $1.4 billion for the three month periods ended March 31, 2021 and 2020, respectively. Revenue derived from foreign operations totaled $46.4 million and $45.7 million for the three month periods ended March 31, 2021 and 2020, respectively, substantially all of which was derived from the Company’s Canadian operations in its Oil and Gas segment. Long-lived assets held in the U.S. included property and equipment, net, of $1.0 billion as of both March 31, 2021 and December 31, 2020, and, for the Company’s businesses in foreign countries, totaled $22.2 million and $22.8 million, respectively. Intangible assets and goodwill, net, related to the Company’s U.S. operations totaled approximately $1.4 billion as of both March 31, 2021 and December 31, 2020, and for the Company’s businesses in foreign countries, totaled approximately $49.4 million and $50.5 million as of March 31, 2021 and December 31, 2020, respectively. The majority of the Company’s long-lived and intangible assets and goodwill in foreign countries relate to its Canadian operations. As of both March 31, 2021 and December 31, 2020, amounts due from customers from which foreign revenue was derived accounted for approximately 5%, respectively, of the Company’s consolidated net accounts receivable position, which represents accounts receivable, net, less deferred revenue. Revenue from governmental entities for the three month periods ended March 31, 2021 and 2020 totaled approximately 4% and 2%, respectively, of total revenue, substantially all of which 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 March 31, Customer: 2021 2020 Enbridge, Inc. (a) 25% 1% AT&T (b) 11% 24% (a) The Company’s relationship with Enbridge, Inc. is based upon various construction contracts for pipeline activities, for which the related revenue is included within the Oil and Gas segment. (b) 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. Revenue from AT&T is included within the Communications segment. The decrease in AT&T revenue for the three month period ended March 31, 2021 as compared with the same period in 2020 was primarily driven by lower levels of wireless services, including from the effects of the COVID-19 pandemic and temporary project timing delays related to recently completed 5G spectrum auctions.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021 and December 31, 2020, there were $153.2 million and $151.8 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 March 31, 2021 or December 31, 2020. 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 March 31, 2021 and December 31, 2020, outstanding performance and payment bonds approximated $1,739.7 million and $764.8 million, respectively, and estimated costs to complete projects secured by these bonds totaled $773.7 million and $263.2 million as of March 31, 2021 and December 31, 2020, respectively. Included in these balances as of March 31, 2021 are $115.0 million of outstanding performance and payment bonds issued on behalf of the Company’s proportionately consolidated non-controlled contractual joint ventures, representing the Company’s proportionate share of the total bond obligation for the related projects. 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 undivided interests ranging from 30% to 50% in three civil construction projects. 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 March 31, 2021, the Company was not aware of material future claims against it in connection with these arrangements. Included in the Company’s cash balances as of March 31, 2021 and December 31, 2020 are amounts held by entities that are proportionately consolidated totaling $7.6 million and $8.2 million, respectively. These amounts are available to support the operations of those entities, but are not available for the Company’s other operations. In addition, the Company provided $0.7 million of project-related financing to its contractual joint ventures for the three month period ended March 31, 2021. 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 and Note 15 - Related Party Transactions for additional information pertaining to the Company’s 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 March 31, 2021 and December 31, 2020, MasTec’s estimated liability for unpaid claims and associated expenses, including incurred but not reported losses related to these policies, totaled $136.3 million and $129.6 million, respectively, of which $89.0 million and $86.1 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 $5.3 million and $4.3 million as of March 31, 2021 and December 31, 2020, 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 as of both March 31, 2021 and December 31, 2020. Outstanding surety bonds related to self-insurance programs amounted to $37.4 million as of both March 31, 2021 and December 31, 2020. 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 March 31, 2021, 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 March 31, 2021 and December 31, 2020, 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 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.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2021
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, sells certain supplies, 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 March 31, 2021 and 2020, such payments to related party entities totaled approximately $20.5 million and $25.3 million, respectively. Payables associated with such arrangements totaled approximately $10.4 million and $8.9 million as of March 31, 2021 and December 31, 2020, respectively. Revenue from such related party arrangements totaled approximately $1.1 million and $1.0 million for the three month periods ended March 31, 2021 and 2020, respectively. Related amounts receivable, net, totaled approximately $0.2 million and $0.5 million as of March 31, 2021 and December 31, 2020, respectively. 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, net, totaled approximately $0.2 million and $0.1 million as of March 31, 2021 and December 31, 2020, respectively, which amounts are expected to be settled under customary terms associated with the related purchase agreement. The Company rents and leases equipment, and purchases certain supplies and servicing from CCI. 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. For the three month periods ended March 31, 2021 and 2020, MasTec paid CCI $5.0 million and $0.3 million, net of rebates, respectively, related to this activity. Amounts payable to CCI, net of rebates receivable, totaled approximately $4.6 million and $4.2 million as of March 31, 2021 and December 31, 2020, respectively. The Company has also rented equipment to CCI. Revenue from equipment rentals to CCI totaled approximately $0.1 million for the three month period ended March 31, 2021, for which related receivables totaled approximately $0.1 million as of March 31, 2021, and as of December 31, 2020, were de minimis. MasTec has a subcontracting arrangement with an entity for the performance of construction services, the minority owners of which include an entity controlled by Jorge Mas and José R. Mas, along with two members of management of a MasTec subsidiary. For the three month periods ended March 31, 2021 and 2020, MasTec incurred subcontracting expenses of approximately $29.0 million and $0.7 million, respectively, under these arrangements. As of March 31, 2021 and December 31, 2020, related amounts payable totaled approximately $18.6 million and $1.4 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 March 31, 2021 and 2020, MasTec paid approximately $0.6 million related to this leasing arrangement. 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. For the three month period ended March 31, 2021, charges under these arrangements were de minimis, and for the three month period ended March 31, 2020, MasTec charged approximately $4.0 million. Related amounts outstanding as of both March 31, 2021 and December 31, 2020 were de minimis. Payments for other expenses related to the Franchise for the three month periods ended March 31, 2021 and 2020 totaled approximately $0.1 million and $0.2 million, respectively, for which there were no amounts outstanding as of either March 31, 2021 or December 31, 2020. MasTec leases employees and provides satellite communications services to a customer in which Jorge Mas and José R. Mas own a majority interest. For both the three month periods ended March 31, 2021 and 2020, charges to this customer under these arrangements totaled approximately $0.3 million. As of March 31, 2021 and December 31, 2020, related amounts receivable totaled approximately $0.8 million and $0.9 million, respectively. The Company, through a second quarter 2020 acquisition, has a 25% interest in an entity, under which the acquired business and the 25%-owned entity have a subcontracting arrangement. The Company’s interest in this entity, for which post-acquisition operating activity is de minimis, is accounted for as an equity method investment. As of both March 31, 2021 and December 31, 2020, the Company’s net investment in this entity was a liability of approximately $2.0 million, which net amount includes approximately $1.9 million of accounts receivable, net, less deferred revenue, related to the subcontracting arrangement. Additionally, the Company has certain arrangements with an entity in which members of management have an ownership interest, including a fee arrangement in conjunction with a $15.0 million letter of credit issued by the Company on behalf of this entity. For the three month period ended March 31, 2021, approximately $0.2 million of income was recognized in connection with these arrangements. As of March 31, 2021 and December 31, 2020, related amounts receivable totaled $0.6 million and $0.4 million, respectively. Split Dollar Agreements

Business, Basis of Presentati_2

Business, Basis of Presentation and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
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, 2020 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, 2020 contained in the Company’s 2020 Annual Report on Form 10-K (the “2020 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 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 applies the equity method of accounting for its investments in entities for which it does not have a controlling financial interest, but over which it has the ability to exert significant influence. See Note 4 - Fair Value of Financial Instruments. 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 applies the equity method of accounting for its investments in entities for which it does not have a controlling financial interest, but over which it has the ability to exert significant influence. See Note 4 - Fair Value of Financial Instruments.
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. For foreign operations for which the local currency is not the functional currency, the operation’s non-monetary assets are remeasured into U.S. dollars at historical exchange rates. All other accounts are remeasured at current exchange rates. Gains or losses from remeasurement are included in other income or expense, net. 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 that management believes to be reasonable under the circumstances, including the potential future effects of the COVID-19 pandemic, climate change, and other relevant global and/or macroeconomic trends and 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 these 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
COVID-19 Disclosure	COVID-19 Pandemic During the first quarter of 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 disrupted business activities and significantly affected global economic conditions in 2020 and continuing into 2021 as federal, state and local governments imposed restrictions and mitigation measures to address the public health crisis, the effects of which resulted in workforce, supply chain and production disruptions and created significant uncertainties in the U.S. and global economies. While the adverse effects of these restrictions and mitigation measures partially subsided in the second half of 2020 and into 2021, the possibility of future restrictions remains in the event of a rise in the number of COVID-19 cases in the future. As a provider of essential services, all of the Company’s business segments continued to operate throughout 2020 and into 2021, and where safe and possible, the Company’s customers generally directed it to maintain normal work schedules. The Company’s business model has, thus far, proven resilient, and management continues to adapt to the changing operational and economic environment that has resulted from the COVID-19 pandemic. Management’s top priority has been to take appropriate actions to protect the health and safety of its employees, customers and business partners. The Company has adjusted its standard operating procedures within its business operations to ensure employee and customer safety, and is continually monitoring evolving health guidelines and responding to changes as appropriate. The COVID-19 pandemic had a negative impact on the Company’s operations in 2020 and is expected to continue to affect its business activities in 2021. These impacts include lost productivity from governmental permitting approval delays, reduced crew productivity due to social distancing, other mitigation measures and 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. Several relief measures have been enacted in response to the effects of the COVID-19 pandemic, including the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) and the Coronavirus Response and Relief Supplemental Appropriations Act (the “Coronavirus Relief Act”). The CARES Act permitted deferral and/or reduction of certain federal and payroll tax amounts, certain of which the Company pursued, including the deferral of approximately $59 million of payroll taxes, half of which are due by December 31, 2021, with the remainder due by December 31, 2022. The Company will continue to monitor and evaluate the potential effects, usefulness of, and qualification for, additional COVID-19 relief measures on the Company’s financial position, results of operations and cash flows. Notwithstanding moderation of the COVID-19 pandemic and easing of governmental and other restrictions, the Company may continue to experience negative effects on its business and operations from possible longer-term changes in consumer and customer behavior, and/or from continuing negative economic conditions. The Company believes that it has taken appropriate steps to mitigate the impacts of the COVID-19 pandemic on its business; however, the potential effects of the COVID-19 pandemic are uncertain, as they depend upon numerous evolving factors that management may not be able to accurately predict. The availability of effective treatments and vaccines, the speed with which they can be administered to the public, the degree to which the public is willing to be vaccinated and the degree that vaccines are effective in preventing infection or illness from existing or new strains of COVID-19, along with the length and extent of any continuing economic and market disruptions are unknown, and, therefore, any future impacts on our business, financial condition and/or results of operations 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 28% and 42% of consolidated revenue for the three month periods ended March 31, 2021 and 2020, 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 5% and 6% of consolidated revenue for the three month periods ended March 31, 2021 and 2020, respectively. 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 three month periods ended March 31, 2021 and 2020, 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, 2020 and 2019. Revenue recognized for the three month periods ended March 31, 2021 and 2020 as a result of changes in total contract transaction price estimates, including from variable consideration, from performance obligations satisfied or partially satisfied in prior periods, totaled approximately $13.8 million and $17.8 million, 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 $3.7 million and $5.5 million as of March 31, 2021 and December 31, 2020. 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 March 31, 2021, the amount of the Company’s remaining performance obligations was $5.0 billion. Based on current expectations, the Company expects to recognize approximately $4.0 billion of its remaining performance obligations as revenue during 2021, with the majority of the remaining balance to be recognized in 2022. 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 March 31, 2021 and December 31, 2020, the Company included approximately $59 million and $51 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 March 31, 2021 and December 31, 2020, these change orders and/or claims related to projects across the Company’s 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 The discussion below describes the effects of recent accounting pronouncements, as updated from the discussion in the Company’s 2020 Form 10-K. Accounting Pronouncements Adopted in 2021 In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which eliminates certain exceptions to the existing guidance for income taxes related to the approach for intra-period tax allocations, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. This ASU also simplifies the accounting for income taxes by clarifying and amending existing guidance related to the effects of enacted changes in tax laws or rates in the effective tax rate computation, the recognition of franchise tax and the evaluation of a step-up in the tax basis of goodwill, among other clarifications. ASU 2019-12, which the Company adopted during the first quarter of 2021, did not have a material effect on the Company’s consolidated financial statements.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021 2020 Net income attributable to MasTec: Net income - basic and diluted (a) $ 65,649 $ 36,230 Weighted average shares outstanding: Weighted average shares outstanding - basic 72,439 74,738 Dilutive common stock equivalents (b) 1,407 675 Weighted average shares outstanding - diluted 73,846 75,413 (a) Calculated as total net income less amounts attributable to non-controlling interests. (b) For the three month period ended March 31, 2021, there were 22,527 anti-dilutive common stock equivalents.

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill by Segment	The following table provides balances for goodwill by reportable segment as of March 31, 2021 (in millions): Communications Clean Energy and Infrastructure Oil and Gas Electrical Total Goodwill Goodwill, gross $ 561.9 $ 166.4 $ 509.7 $ 150.1 $ 1,388.1 Accumulated impairment loss — — (125.4) — (125.4) Goodwill, net $ 561.9 $ 166.4 $ 384.3 $ 150.1 $ 1,262.7
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 Customer Relationships and Backlog Pre-Qualifications Other (a) Total Other intangible assets, gross, as of December 31, 2020 $ 34.5 $ 297.9 $ 73.8 $ 26.4 $ 432.6 Accumulated amortization (218.5) (10.6) (19.5) (248.6) Other intangible assets, net, as of December 31, 2020 $ 34.5 $ 79.4 $ 63.2 $ 6.9 $ 184.0 Additions from new business combinations — 48.0 — 4.3 52.3 Currency translation adjustments — — 0.5 — 0.5 Amortization expense (7.9) (2.7) (0.6) (11.2) Other intangible assets, net, as of March 31, 2021 $ 34.5 $ 119.5 $ 61.0 $ 10.6 $ 225.6 (a) Consists principally of trade names and non-compete agreements.

Accounts Receivable, Net of A_2

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
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): March 31, December 31, Contract billings $ 889.5 $ 805.0 Less allowance (12.8) (20.5) Accounts receivable, net of allowance $ 876.7 $ 784.5 Retainage 314.0 287.7 Unbilled receivables 644.1 682.0 Contract assets $ 958.1 $ 969.7

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2021
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): March 31, December 31, Land $ 8.4 $ 6.0 Buildings and leasehold improvements 43.7 40.5 Machinery and equipment 1,972.1 1,875.5 Office furniture and equipment 228.3 221.6 Construction in progress 23.0 26.1 Total property and equipment $ 2,275.5 $ 2,169.7 Less accumulated depreciation and amortization (1,251.0) (1,187.4) Property and equipment, net $ 1,024.5 $ 982.3

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2021
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 March 31, December 31, Senior secured credit facility: September 19, 2024 Revolving loans $ 45.0 $ 32.7 Term loan 395.0 397.5 4.50% Senior Notes August 15, 2028 600.0 600.0 Finance lease and other obligations 302.9 288.5 Total debt obligations $ 1,342.9 $ 1,318.7 Less unamortized deferred financing costs (15.2) (16.0) Total debt, net of deferred financing costs $ 1,327.7 $ 1,302.7 Current portion of long-term debt 157.3 145.1 Long-term debt $ 1,170.4 $ 1,157.6

Lease Obligations (Tables)

Lease Obligations (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Schedule of Future Minimum Lease Commitments, Finance Leases	Future minimum lease commitments as of March 31, 2021 were as follows (in millions): Finance Leases Operating 2021, remaining nine months $ 115.4 $ 63.1 2022 115.3 51.5 2023 61.7 27.3 2024 22.5 17.3 2025 2.1 10.8 Thereafter — 19.8 Total minimum lease payments $ 317.0 $ 189.8 Less amounts representing interest (14.2) (13.6) Total lease obligations, net of interest $ 302.8 $ 176.2 Less current portion 142.2 69.2 Long-term portion of lease obligations, net of interest $ 160.6 $ 107.0
Schedule of Future Minimum Lease Commitments, Operating Leases	Future minimum lease commitments as of March 31, 2021 were as follows (in millions): Finance Leases Operating 2021, remaining nine months $ 115.4 $ 63.1 2022 115.3 51.5 2023 61.7 27.3 2024 22.5 17.3 2025 2.1 10.8 Thereafter — 19.8 Total minimum lease payments $ 317.0 $ 189.8 Less amounts representing interest (14.2) (13.6) Total lease obligations, net of interest $ 302.8 $ 176.2 Less current portion 142.2 69.2 Long-term portion of lease obligations, net of interest $ 160.6 $ 107.0

Stock-Based Compensation and _2

Stock-Based Compensation and Other Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2021
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, 2020 1,845,341 $ 34.90 Granted 146,681 92.29 Vested (110,662) 51.44 Canceled/forfeited (8,400) 29.80 Non-vested restricted shares, as of March 31, 2021 1,872,960 $ 38.44 (a) Includes 2,500 and 2,300 restricted stock units as of March 31, 2021 and December 31, 2020, respectively.

Other Retirement Plans (Tables)

Other Retirement Plans (Tables)	3 Months Ended
	Mar. 31, 2021
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 March 31: 2021 2,412 2,532 $ 22.5 $ 2.2 $ 24.7 2020 1,119 1,424 $ 5.4 $ 1.7 $ 7.1

Segments and Related Informat_2

Segments and Related Information (Tables)	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Schedule of Financial Information by Reportable Segment	For the Three Months Ended March 31, Revenue: 2021 2020 Communications (a) $ 568.6 $ 644.1 Clean Energy and Infrastructure 350.4 286.3 Oil and Gas 725.5 359.1 Electrical Transmission 133.5 128.1 Other 0.0 0.0 Eliminations (2.6) (1.0) Consolidated revenue $ 1,775.4 $ 1,416.6 (a) Revenue generated primarily by utilities customers represented 20.1% and 15.2% of Communications segment revenue for the three month periods ended March 31, 2021 and 2020, respectively. For the Three Months Ended March 31, EBITDA: 2021 2020 Communications $ 48.9 $ 50.8 Clean Energy and Infrastructure 10.9 5.0 Oil and Gas 167.6 74.4 Electrical Transmission 3.6 8.3 Other 7.4 7.4 Corporate (40.0) (31.9) Consolidated EBITDA $ 198.4 $ 114.0 For the Three Months Ended March 31, Depreciation and Amortization: 2021 2020 Communications $ 21.8 $ 19.7 Clean Energy and Infrastructure 7.6 4.0 Oil and Gas 52.1 28.1 Electrical Transmission 6.1 5.9 Other 0.0 0.0 Corporate 2.9 2.8 Consolidated depreciation and amortization $ 90.5 $ 60.5
Reconciliation of Consolidated Income before Income Taxes to EBITDA	For the Three Months Ended March 31, EBITDA Reconciliation: 2021 2020 Income before income taxes $ 95.4 $ 36.5 Plus: Interest expense, net 12.5 17.0 Depreciation 79.3 53.1 Amortization of intangible assets 11.2 7.4 Consolidated EBITDA $ 198.4 $ 114.0
Schedule of Revenue by Major Customers by Reporting Segments	Revenue concentration information for significant customers as a percentage of total consolidated revenue was as follows: For the Three Months Ended March 31, Customer: 2021 2020 Enbridge, Inc. (a) 25% 1% AT&T (b) 11% 24% (a) The Company’s relationship with Enbridge, Inc. is based upon various construction contracts for pipeline activities, for which the related revenue is included within the Oil and Gas segment. (b) 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. Revenue from AT&T is included within the Communications segment. The decrease in AT&T revenue for the three month period ended March 31, 2021 as compared with the same period in 2020 was primarily driven by lower levels of wireless services, including from the effects of the COVID-19 pandemic and temporary project timing delays related to recently completed 5G spectrum auctions.

Business, Basis of Presentati_3

Business, Basis of Presentation and Significant Accounting Policies (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)numberOfSegments	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Number of reportable segments | numberOfSegments	5
Accrued payroll taxes	$ 59
Revenue [Line Items]
Revenue recognition, performance obligations satisfied in previous periods, revenue recognized (in dollars)	13.8	$ 17.8
Contract with customer, unapproved change orders and/or claims, amount (in dollars)	59		$ 51
Mobilization Costs
Revenue [Line Items]
Mobilization costs	$ 3.7		$ 5.5
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	28.00%	42.00%
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	5.00%	6.00%

Business, Basis of Presentati_4

Business, Basis of Presentation and Significant Accounting Policies (Remaining Performance Obligations) (Narrative) (Details) $ in Billions	Mar. 31, 2021USD ($)
Accounting Policies [Abstract]
Revenue recognition, remaining performance obligations, contract price allocated (in dollars)	$ 5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Accounting Policies [Abstract]
Revenue recognition, remaining performance obligations, contract price allocated (in dollars)	$ 4
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) - Accounting Standards Update 2019-12	Mar. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true

Earnings Per Share (Schedule of

Earnings Per Share (Schedule of Earnings Per Share Information) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net income attributable to MasTec:
Net income - basic (in dollars)	$ 65,649	$ 36,230
Net income - diluted (in dollars)	$ 65,649	$ 36,230
Weighted average shares outstanding:
Weighted average shares outstanding - basic	72,439,000	74,738,000
Dilutive common stock equivalents (in shares)	1,407,000	675,000
Weighted average shares outstanding - diluted	73,846,000	75,413,000
Anti-dilutive common stock (in shares)	22,527

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Schedule of Goodwill by Segment) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill, gross	$ 1,388,100
Accumulated impairment loss	(125,400)
Goodwill, net	1,262,718	$ 1,243,034
Communications [Member]
Goodwill [Line Items]
Goodwill, gross	561,900
Accumulated impairment loss	0
Goodwill, net	561,900
Clean Energy and Infrastructure [Member]
Goodwill [Line Items]
Goodwill, gross	166,400
Accumulated impairment loss	0
Goodwill, net	166,400
Oil and Gas [Member]
Goodwill [Line Items]
Goodwill, gross	509,700
Accumulated impairment loss	(125,400)
Goodwill, net	384,300
Electrical Transmission [Member]
Goodwill [Line Items]
Goodwill, gross	150,100
Accumulated impairment loss	0
Goodwill, net	$ 150,100

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)
Goodwill [Line Items]
Goodwill, acquired during period	$ 19.7
Goodwill, measurement period adjustments	(0.2)
Goodwill, Gross [Member]
Goodwill [Line Items]
Goodwill, currency translation gains (losses)	1.8
Goodwill, Accumulated Impairment Loss [Member]
Goodwill [Line Items]
Goodwill, currency translation gains (losses)	$ (1.6)

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets (Rollforward of Other Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Other Intangible Assets [Line Items]
Other intangible assets, gross		$ 432,600
Accumulated amortization		(248,600)
Other Intangible Assets [Rollforward]
Other intangible assets, net, beginning balance	$ 184,043
Additions from new business combinations	52,300
Currency translation adjustments	500
Amortization expense	(11,200)
Other intangible assets, net, ending balance	225,566
Customer Relationships and Backlog [Member]
Other Intangible Assets [Line Items]
Other intangible assets, amortizing, gross		297,900
Accumulated amortization		(218,500)
Other Intangible Assets [Rollforward]
Other intangible assets, net, amortizing, beginning balance	79,400
Additions from new business combinations, amortizing intangible assets	48,000
Currency translation adjustments, amortizing intangible assets	0
Amortization expense	(7,900)
Other intangible assets, net, amortizing, ending balance	119,500
Pre-Qualifications [Member]
Other Intangible Assets [Line Items]
Other intangible assets, amortizing, gross		73,800
Accumulated amortization		(10,600)
Other Intangible Assets [Rollforward]
Other intangible assets, net, amortizing, beginning balance	63,200
Additions from new business combinations, amortizing intangible assets	0
Currency translation adjustments, amortizing intangible assets	500
Amortization expense	(2,700)
Other intangible assets, net, amortizing, ending balance	61,000
Other Amortizing Intangible Assets [Member]
Other Intangible Assets [Line Items]
Other intangible assets, amortizing, gross		26,400
Accumulated amortization		(19,500)
Other Intangible Assets [Rollforward]
Other intangible assets, net, amortizing, beginning balance	6,900
Additions from new business combinations, amortizing intangible assets	4,300
Currency translation adjustments, amortizing intangible assets	0
Amortization expense	(600)
Other intangible assets, net, amortizing, ending balance	10,600
Trade Names [Member]
Other Intangible Assets [Line Items]
Other intangible assets, non-amortizing	34,500	$ 34,500
Other Intangible Assets [Rollforward]
Other intangible assets, non-amortizing, beginning balance	34,500
Additions from new business combinations, non-amortizing intangible assets	0
Currency translation adjustments, non-amortizing intangible assets	0
Other intangible assets, non-amortizing, ending balance	$ 34,500

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets (Quarterly Assessment for Indicators of Impairment) (Narrative) (Details)	3 Months Ended
	Mar. 31, 2021reportingunit
Oil and Gas [Member]
Goodwill [Line Items]
Number of reporting units	1

Goodwill and Other Intangible_7

Goodwill and Other Intangible Assets (2021 Acquisitions) (Narrative) (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021USD ($)acquisition	Mar. 31, 2020USD ($)	Dec. 31, 2020acquisition
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition	2		5
Business combinations, cash, net of cash acquired	$ 88,646	$ 0
2021 Acquisitions
Business Acquisition [Line Items]
Business combinations, cash, net of cash acquired	$ 90,000

Goodwill and Other Intangible_8

Goodwill and Other Intangible Assets (2020 Acquisitions) (Narrative) (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021USD ($)acquisition	Mar. 31, 2020USD ($)	Dec. 31, 2023USD ($)	Dec. 31, 2020yracquisition	Jun. 30, 2020
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition	2			5
Business combinations, cash, net of cash acquired	$ 88,646	$ 0
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, low	56,000
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high	$ 174,000
Install to Home
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition				1
Clean Energy and Infrastructure and Communications
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition				2,000,000
Clean Energy and Infrastructure [Member]
Business Acquisition [Line Items]
Business combinations, percentage of interests acquired	91.00%			91.00%	96.00%
Communications and Electrical Transmission
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition				3
Communications [Member]
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition				1
Electrical Transmission [Member]
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition				1
2020 Acquisitions [Member]
Business Acquisition [Line Items]
Business combinations, cash, net of cash acquired	$ 23,500
Business combinations, contingent consideration, earn-out liabilities	8,300
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, low	1,000
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high	$ 13,000
2020 Acquisitions [Member] | Maximum [Member] | Expected Term [Member]
Business Acquisition [Line Items]
Business combinations, contingent consideration, earn-out period (in years) | yr				5
2020 Acquisitions [Member] | Forecast [Member]
Business Acquisition [Line Items]
Business combinations, cash, net of cash acquired			$ 3,200

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
	Mar. 31, 2021	Mar. 31, 2020
Pro Forma Financial Information and Acquisition Results [Abstract]
Business combinations, unaudited supplemental pro forma revenue	$ 1,800	$ 1,600
Business combinations, unaudited supplemental pro forma net income (loss)	68.6	46.7
Business combinations, consolidated acquisition-related revenue	86.8	49.5
Business combinations, consolidated acquisition-related income (loss)	$ 1.2	$ (1.2)

Goodwill and Other Intangibl_10

Goodwill and Other Intangible Assets (Q2 2021 Acquisitions) (Details) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	May 06, 2021USD ($)numberOfEmployees	Mar. 31, 2021USD ($)acquisition	Mar. 31, 2020USD ($)	Dec. 31, 2020acquisition
Business Acquisition [Line Items]
Business combinations, number of acquisitions | acquisition		2		5
Business combinations, cash, net of cash acquired		$ 88,646	$ 0
Subsequent Event [Member]
Business Acquisition [Line Items]
Business combinations, number of acquisitions | numberOfEmployees	2
2021 Acquisitions
Business Acquisition [Line Items]
Business combinations, cash, net of cash acquired		$ 90,000
2021 Acquisitions | Subsequent Event [Member]
Business Acquisition [Line Items]
Business combinations, cash, net of cash acquired	$ 420,000

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Acquisition-Related Contingent Consideration and Other Liabilities) (Narrative) (Details)	3 Months Ended
	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, low	$ 56,000,000
Acquisition-related contingent consideration liabilities, range of potential undiscounted earn-out liabilities, high	174,000,000
Acquisition-related contingent consideration liabilities, net increase (decrease), measurement period adjustments	$ (200,000)
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
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	0.200
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	0.131
Earn-Out Liabilities [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Acquisition-related contingent consideration liabilities, estimated fair value	$ 134,800,000		$ 135,200,000
Acquisition-related contingent consideration liabilities, additions from new business combinations	0	$ 0
Acquisition-related contingent consideration liabilities, net increase (decrease), measurement period adjustments	0	1,100,000
Acquisition-related contingent consideration liabilities, net increase (decrease), fair value adjustments, expense (income)	(400,000)	1,800,000
Acquisition-related contingent consideration liabilities, payments	0	$ 0
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	$ 47,900,000		$ 48,100,000

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Equity Investments) (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investments, carrying value	$ 242,000,000		$ 220,000,000
Equity investments, adjusted cost basis, amount	18,000,000		17,000,000
Equity investments, impairments	0	$ 0
Loans Receivable [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Financing receivables	$ 3,000,000		3,000,000
Financing commitments			3,000,000
Waha JVs [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, ownership percentage	33.00%
Equity investments, carrying value	$ 196,000,000		175,000,000
CCI [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investments, adjusted cost basis, amount	$ 15,000,000
CCI [Member] | Immediate Family Member of Management [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investments without readily determinable fair value, ownership percentage	15.00%
FM Tech [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, ownership percentage	50.00%
Equity investments, carrying value	$ 17,000,000		$ 16,000,000

Fair Value of Financial Instr_4

Fair Value of Financial Instruments (The Waha JVs) (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, equity in earnings (losses)	$ 7,346,000	$ 7,834,000
Equity method investments, net investment	242,000,000		$ 220,000,000
Unrealized gains (losses) on equity investee activity, net of tax	13,839,000	(22,961,000)
Waha JVs [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, equity in earnings (losses)	7,700,000	7,600,000
Equity method investments, distributions of earnings received, operating cash flows	0	2,600,000
Equity method investments, cumulative undistributed earnings	75,000,000
Equity method investments, net investment	196,000,000		$ 175,000,000
Unrealized gains (losses) on equity investee activity, before tax	17,300,000	(30,300,000)
Unrealized gains (losses) on equity investee activity, net of tax	$ 13,100,000	$ (23,000,000)

Fair Value of Financial Instr_5

Fair Value of Financial Instruments (Other Investments - AVCT) (Narrative) (Details) - AVCT [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Equity investment ownership, percentage	9.00%	9.00%
Beneficial ownership of all interests, percentage	22.00%	21.00%
Equity investment and warrants, amount paid (in dollars)	$ 5
Unrealized fair value measurement gains (losses), AVCT shares	(1)
Unrealized gains (losses) on AVCT convertible debentures, before tax	1
Unrealized gains (losses) on AVCT convertible debentures, net of tax	0.8
Common Stock [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Equity securities, fair value	$ 17	$ 17

Fair Value of Financial Instr_6

Fair Value of Financial Instruments (Other Investments - Other Equity Method Investments) (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, net investment	$ 242,000,000		$ 220,000,000
Loans Receivable [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Financing commitments			3,000,000
Confluence [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, ownership percentage	75.00%
Equity method investments, net investment	$ 400,000
Confluence [Member] | Loans Receivable [Member] | Maximum [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Financing commitments	2,500,000
Telecommunications Equity Method Investees [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, net investment	21,000,000		19,000,000
Equity method investments, equity contributions	2,000,000	$ 0
Receivables, related party	200,000
Payments for advance to affiliate	200,000
Telecommunications Equity Method Investees [Member] | Subcontracting Arrangements [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Expenses, related party	1,800,000	$ 2,700,000
Payables, related party	300,000		200,000
Telecommunications Equity Method Investees [Member] | Employee Leasing Arrangement
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Receivables, related party	$ 500,000		400,000
FM Tech [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, ownership percentage	50.00%
Equity method investments, net investment	$ 17,000,000		16,000,000
Equity method investments, equity contributions	2,000,000
FM Tech [Member] | Equity Method Investments [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Financing commitments	$ 3,000,000		$ 9,000,000

Fair Value of Financial Instr_7

Fair Value of Financial Instruments (Senior Notes) (Narrative) (Details) - 4.50% Senior Notes [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Fair Value Disclosure of Liabilities Not Measured at Fair Value [Line Items]
Senior Notes, gross carrying amount	$ 600
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	$ 618	$ 625.5

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	Mar. 31, 2021	Dec. 31, 2020
Receivables [Abstract]
Contract billings	$ 889,500	$ 805,000
Less allowance	(12,800)	(20,500)
Accounts receivable, net of allowance	876,715	784,488
Contract Assets [Abstract]
Retainage	314,000	287,700
Unbilled receivables	644,100	682,000
Contract assets	$ 958,064	$ 969,743

Accounts Receivable, Net of A_4

Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Provision for credit losses	$ (7,700)	$ 1,600
Contract liabilities	259,488		$ 228,388
Contract with customer liability, deferred revenue current	240,800		$ 203,000
Deferred revenue, revenue recognized	146,800	105,600
Non-recourse financing agreement, discount charge	(12,459)	(17,004)
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	$ (800)	$ (1,800)
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	Mar. 31, 2021	Dec. 31, 2020
Property and Equipment [Line Items]
Property and equipment	$ 2,275,500	$ 2,169,700
Less accumulated depreciation and amortization	(1,251,000)	(1,187,400)
Property and equipment, net	1,024,509	982,328
Land [Member]
Property and Equipment [Line Items]
Property and equipment	8,400	6,000
Building and Leasehold Improvements [Member]
Property and Equipment [Line Items]
Property and equipment	43,700	40,500
Machinery and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment	1,972,100	1,875,500
Office Furniture and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment	228,300	221,600
Construction in Progress [Member]
Property and Equipment [Line Items]
Property and equipment	$ 23,000	$ 26,100

Property and Equipment, Net (Na

Property and Equipment, Net (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Capitalized internal-use software, gross	$ 160.2	$ 154.1
Capitalized internal-use software, net	$ 36.7	$ 34.3

Debt (Schedule of Carrying Valu

Debt (Schedule of Carrying Values of Debt) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Finance lease and other obligations	$ 302,900	$ 288,500
Total debt obligations	1,342,900	1,318,700
Less unamortized deferred financing costs	(15,200)	(16,000)
Total debt, net of deferred financing costs	1,327,700	1,302,700
Current portion of long-term debt	157,257	145,110
Long-term debt	$ 1,170,419	1,157,632
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	$ 45,000	32,700
Credit Facility [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Long-term debt obligations	395,000	397,500
Senior Notes [Member] | 4.50% Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt obligations	$ 600,000	$ 600,000
Debt instrument, interest rate (percentage)	4.50%
Debt instrument, maturity date	Aug. 15, 2028

Debt (Senior Secured Credit Fac

Debt (Senior Secured Credit Facility) (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Line of credit facility, letters of credit issued	$ 153.2	$ 151.8		$ 151.8
Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	1,750
Line of credit facility, letters of credit issued	$ 127	$ 133.6		133.6
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	$ 1,200	$ 1,200		$ 1,200
Credit Facility [Member] | Revolving Loans [Member] | Weighted Average [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	1.77%	1.87%		1.87%
Credit Facility [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 400
Line of credit facility, term loan, amount of quarterly principal installment payments				$ 2.5
Line of credit facility, interest rate (percentage)	1.36%	1.40%		1.40%
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
Credit Facility [Member] | Foreign Denomination [Member]
Debt Instrument [Line Items]
Long-term line of credit	$ 45	$ 33		$ 33
Line of credit facility, remaining borrowing capacity	255	267.3		267.3
Credit Facility [Member] | Letters of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, capacity available for letters of credit	$ 523	$ 516.4		$ 516.4
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%		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%		1.25%

Debt (Other Credit Facilities)

Debt (Other Credit Facilities) (Narrative) (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Letters of credit issued	$ 153,200,000	$ 151,800,000
Other Credit Facilities [Member]
Debt Instrument [Line Items]
Long-term debt obligations	0	0
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	$ 26,200,000	$ 18,200,000
Standby Letters of Credit [Member] | Line of Credit [Member] | Letters of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate (percentage)	0.40%	0.50%

Debt (Additional Information) (

Debt (Additional Information) (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt instruments, accrued interest payable (in dollars)	$ 4.8	$ 12.4

Lease Obligations (Additional L

Lease Obligations (Additional Lease Information) (Narrative) (Details)	3 Months Ended
	Mar. 31, 2021
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	3.70%
Operating leases, weighted average remaining lease term (in years)	3 years 10 months 24 days
Operating leases, weighted average discount rate, percent	3.50%
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	8 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
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Leases [Abstract]
Finance leases, assets, gross	$ 591.3		$ 563
Finance leases, assets, net	439.1		$ 418.7
Finance leases, assets, depreciation	$ 19	$ 15.8

Lease Obligations (Operating Le

Lease Obligations (Operating Leases) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating Leased Assets [Line Items]
Operating leases, additions	$ 5.5	$ 5.8
Operating leases, expense	27.4	35.3
Operating leases, variable lease costs	2.2	2.9
Operating leases, short-term leases, expense	$ 110.1	$ 77.5
Minimum [Member]
Operating Leased Assets [Line Items]
Operating leases, term of contract (in years)	1 year
Maximum [Member]
Operating Leased Assets [Line Items]
Operating leases, term of contract (in years)	1 year

Lease Obligations (Schedule of

Lease Obligations (Schedule of Future Minimum Lease Commitments) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Finance Leases
2021, remaining nine months	$ 115,400
2022	115,300
2023	61,700
2024	22,500
2025	2,100
Thereafter	0
Total minimum lease payments	317,000
Less amounts representing interest	(14,200)
Total lease obligations, net of interest	302,800
Less current portion	142,200
Long-term portion of lease obligations, net of interest	160,600
Operating Leases
2021, remaining nine months	63,100
2022	51,500
2023	27,300
2024	17,300
2025	10,800
Thereafter	19,800
Total minimum lease payments	189,800
Less amounts representing interest	(13,600)
Total lease obligations, net of interest	176,200
Less current portion	69,184	$ 72,481
Long-term portion of lease obligations, net of interest	$ 106,971	$ 116,506

Stock-Based Compensation and _3

Stock-Based Compensation and Other Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-based compensation plans, number of shares available for future grant	2,519,000
Non-cash stock-based compensation expense	$ 5.5	$ 4
Stock-based compensation, income tax benefits	1.1	0.9
Stock-based compensation, vested awards, net tax benefits (deficiencies)	$ 0.1	$ (0.1)

Stock-Based Compensation and _4

Stock-Based Compensation and Other Employee Benefit Plans (Restricted Shares) (Narrative) (Details) - Restricted Shares [Member] - USD ($) $ in Millions	Mar. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation awards, unearned compensation	$ 45.7	$ 45.7
Stock-based compensation awards, unearned compensation, weighted average expected recognition period (in years)	2 years 2 months 12 days
Stock-based compensation, vested awards, intrinsic value		$ 10.9	$ 5.6

Stock-Based Compensation and _5

Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Activity, Restricted Shares) (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Restricted Shares [Member]
Restricted Shares
Non-vested restricted shares, beginning balance (in shares)	1,845,341
Granted (in shares)	146,681
Vested (in shares)	(110,662)
Canceled/forfeited (in shares)	(8,400)
Non-vested restricted shares, ending balance (in shares)	1,872,960
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	$ 34.90
Granted (in dollars per share) | $ / shares	92.29
Vested (in dollars per share) | $ / shares	51.44
Canceled/forfeited (in dollars per share) | $ / shares	29.80
Non-vested restricted shares, per share weighted average grant date fair value, ending balance (in dollars per share) | $ / shares	$ 38.44
Restricted Stock Units [Member]
Restricted Shares
Non-vested restricted shares, beginning balance (in shares)	2,300
Non-vested restricted shares, ending balance (in shares)	2,500

Stock-Based Compensation and _6

Stock-Based Compensation and Other Employee Benefit Plans (ESPP) (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Common shares issued (in shares)	18,843	53,399
Cash proceeds (in dollars)	$ 0	$ 1,476
Employee Stock Purchase Plans [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
ESPP purchase price, percent	85.00%
Cash proceeds (in dollars)	$ 1,400	1,500
Compensation expense	$ 300	$ 400

Other Retirement Plans (Schedul

Other Retirement Plans (Schedule of Covered Employees and Contributions, Multiemployer Plans) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)numberOfEmployees	Mar. 31, 2020USD ($)numberOfEmployees
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer Plan, Employer Contribution, Cost	$ 24.7	$ 7.1
Pension Plan [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer Plan, Employer Contribution, Cost	22.5	5.4
Multiemployer Plans, Other Multiemployer [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer Plan, Employer Contribution, Cost	$ 2.2	$ 1.7
Low [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer plans, covered employees (in number of employees) | numberOfEmployees	2,412	1,119
High [Member]
Covered Employees and Contributions, Multiemployer Plans [Line Items]
Multiemployer plans, covered employees (in number of employees) | numberOfEmployees	2,532	1,424

Equity (Share Activity) (Narrat

Equity (Share Activity) (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 19, 2020	Dec. 21, 2018	Sep. 11, 2018
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)	0	3,600,000
Treasury stock acquired, value		$ 119,426,000
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)		600,000
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)		3,000,000
Treasury stock acquired, value		$ 90,600,000
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
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Consolidated effective tax rate, percent	30.70%	1.20%
Effective income tax rate reconciliation, nondeductible expense, share-based payment arrangement, amount	$ 2.3
Effective income tax rate reconciliation, change in deferred tax assets valuation allowance, amount		$ (9.6)

Segments and Related Informat_3

Segments and Related Information (Narrative) (Details)	3 Months Ended
	Mar. 31, 2021numberOfSegments
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
	Mar. 31, 2021	Mar. 31, 2020
Revenue:
Revenue (in dollars)	$ 1,775,424	$ 1,416,604
Communications [Member] | Customer Concentration Risk [Member] | Revenue [Member] | Utilities [Member]
Revenue:
Utilities customers, percentage of Communications segment revenue	20.10%	15.20%
Reportable Segments [Member] | Communications [Member]
Revenue:
Revenue (in dollars)	$ 568,600	$ 644,100
Reportable Segments [Member] | Clean Energy and Infrastructure [Member]
Revenue:
Revenue (in dollars)	350,400	286,300
Reportable Segments [Member] | Oil and Gas [Member]
Revenue:
Revenue (in dollars)	725,500	359,100
Reportable Segments [Member] | Electrical Transmission [Member]
Revenue:
Revenue (in dollars)	133,500	128,100
Reportable Segments [Member] | Other [Member]
Revenue:
Revenue (in dollars)	0	0
Eliminations [Member]
Revenue:
Revenue (in dollars)	$ (2,600)	$ (1,000)

Segments and Related Informat_5

Segments and Related Information (Schedule of Financial Information by Reportable Segment - EBITDA) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
EBITDA:
EBITDA	$ 198.4	$ 114
Reportable Segments [Member] | Communications [Member]
EBITDA:
EBITDA	48.9	50.8
Reportable Segments [Member] | Clean Energy and Infrastructure [Member]
EBITDA:
EBITDA	10.9	5
Reportable Segments [Member] | Oil and Gas [Member]
EBITDA:
EBITDA	167.6	74.4
Reportable Segments [Member] | Electrical Transmission [Member]
EBITDA:
EBITDA	3.6	8.3
Reportable Segments [Member] | Other [Member]
EBITDA:
EBITDA	7.4	7.4
Corporate [Member]
EBITDA:
EBITDA	$ (40)	$ (31.9)

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
	Mar. 31, 2021	Mar. 31, 2020
Depreciation and Amortization:
Depreciation and amortization	$ 90.5	$ 60.5
Reportable Segments [Member] | Communications [Member]
Depreciation and Amortization:
Depreciation and amortization	21.8	19.7
Reportable Segments [Member] | Clean Energy and Infrastructure [Member]
Depreciation and Amortization:
Depreciation and amortization	7.6	4
Reportable Segments [Member] | Oil and Gas [Member]
Depreciation and Amortization:
Depreciation and amortization	52.1	28.1
Reportable Segments [Member] | Electrical Transmission [Member]
Depreciation and Amortization:
Depreciation and amortization	6.1	5.9
Reportable Segments [Member] | Other [Member]
Depreciation and Amortization:
Depreciation and amortization	0	0
Corporate [Member]
Depreciation and Amortization:
Depreciation and amortization	$ 2.9	$ 2.8

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
	Mar. 31, 2021	Mar. 31, 2020
EBITDA Reconciliation:
Income before income taxes	$ 95,429	$ 36,485
Interest expense, net	12,459	17,004
Depreciation	79,264	53,089
Amortization of intangible assets	11,247	7,391
EBITDA	$ 198,400	$ 114,000

Segments and Related Informat_8

Segments and Related Information (Foreign Operations) (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Segments and Related Information [Line Items]
Revenue			$ 1,775,424	$ 1,416,604
Property and equipment, net	$ 1,024,509	$ 982,328	1,024,509
United States [Member]
Segments and Related Information [Line Items]
Revenue			1,700,000	1,400,000
Property and equipment, net	1,000,000	1,000,000	1,000,000
Intangible assets and goodwill, net	1,400,000	1,400,000	1,400,000
Foreign Operations [Member]
Segments and Related Information [Line Items]
Revenue			46,400	$ 45,700
Property and equipment, net	22,200	22,800	22,200
Intangible assets and goodwill, net	$ 49,400	$ 50,500	$ 49,400
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	5.00%	5.00%
Govermment [Member] | Revenue Benchmark [Member] | Customer Concentration Risk [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total			4.00%	2.00%

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
	Mar. 31, 2021	Mar. 31, 2020
Enbridge, Inc.
Segments and Related Information [Line Items]
Concentration risk, percentage of total	25.00%	1.00%
AT&T [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total	11.00%	24.00%

Commitments and Contingencies (

Commitments and Contingencies (Legal, Letters of Credit, Bonds, Self-Insurance) (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Commitments and Contingencies [Line Items]
Letters of credit issued	$ 153.2	$ 151.8
Self-Insurance [Member] | Workers' Compensation, General and Automobile Policies [Member]
Commitments and Contingencies [Line Items]
Self-insurance reserve	136.3	129.6
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	89	86.1
Self-Insurance [Member] | Employee Group Medical Claims [Member]
Commitments and Contingencies [Line Items]
Self-insurance reserve	5.3	4.3
Performance and Payment Bonds [Member]
Commitments and Contingencies [Line Items]
Bonded projects, estimated costs to complete	773.7	263.2
Performance and Payment Bonds [Member] | Subsidiaries [Member]
Commitments and Contingencies [Line Items]
Outstanding bonds, amount	1,739.7	764.8
Performance and Payment Bonds [Member] | Subsidiaries [Member] | Corporate Joint Venture [Member]
Commitments and Contingencies [Line Items]
Outstanding bonds, amount	115
Financial Guarantees [Member] | Self-Insurance [Member] | Workers' Compensation, General and Automobile Policies [Member]
Commitments and Contingencies [Line Items]
Letters of credit issued	59.3	59.3
Surety Bonds [Member] | Self-Insurance [Member] | Workers' Compensation [Member]
Commitments and Contingencies [Line Items]
Outstanding bonds, amount	$ 37.4	$ 37.4

Commitments and Contingencies_2

Commitments and Contingencies (Investment Arrangements) (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)numberOfEmployees	Dec. 31, 2020USD ($)
Other Commitments [Line Items]
Number of joint ventures | numberOfEmployees	3
Cash	$ 512,407	$ 423,118
Proportionately Consolidated Non-Controlled Joint Venture [Member]
Other Commitments [Line Items]
Cash	7,600	$ 8,200
Payments for advance to affiliate	$ 700
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] | Minimum [Member]
Other Commitments [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage	30.00%
Proportionately Consolidated Non-Controlled Joint Venture [Member] | Joint Venture Civil Construction Project [Member] | Maximum [Member]
Other Commitments [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage	50.00%

Commitments and Contingencies_3

Commitments and Contingencies (Concentrations of Risk) (Narrative) (Details) - numberOfCustomers	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Concentration Risk [Line Items]
Number of customers			330
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	2
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	14.00%	15.00%
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	10.00%	12.00%
Revenue [Member] | Customer Concentration Risk [Member] | Ten Largest Customers [Member]
Concentration Risk [Line Items]
Number of customers			10	10
Concentration risk, percentage of total			68.00%	62.00%

Related Party Transactions (Man

Related Party Transactions (Management) (Narrative) (Details) - Management [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Equipment, Supplies and Services [Member]
Related Party Transaction [Line Items]
Payments, related party	$ 20.5	$ 25.3
Payables, related party	10.4		$ 8.9
Revenue, related party	1.1	1
Receivables, net, related party	0.2		0.5
Subcontracting Arrangements [Member]
Related Party Transaction [Line Items]
Payments, related party	29	$ 0.7
Payables, related party	$ 18.6		$ 1.4

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
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Construction Management Firm Specializing in Steel Building Systems [Member]
Related Party Transaction [Line Items]
Advances outstanding, related party		$ 0.2	$ 0.1
CCI [Member] | Equipment [Member]
Related Party Transaction [Line Items]
Payments, net of rebates, related party	$ 5	$ 0.3
Payables, related party	4.6		$ 4.2
Revenue, related party	0.1
Receivables, related party	$ 0.1

Related Party Transactions (Exe

Related Party Transactions (Executive Officers) (Narrative) (Details)	3 Months Ended
	Mar. 31, 2021USD ($)numberOfEmployees	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Management [Member] | Subcontracting Arrangements [Member]
Related Party Transaction [Line Items]
Number of management members, subcontracting arrangement | numberOfEmployees	2
Expenses, related party	$ 29,000,000	$ 700,000
Payables, related party	18,600,000		$ 1,400,000
Chairman, Board of Directors [Member] | Lease Agreements [Member]
Related Party Transaction [Line Items]
Expenses, related party	600,000	600,000
Executive Officers [Member] | Related Customer [Member]
Related Party Transaction [Line Items]
Receivables, related party	800,000		900,000
Charges, related party	300,000	300,000
Executive Officers [Member] | Construction Services [Member]
Related Party Transaction [Line Items]
Expenses, related party	100,000	200,000
Payables, related party	$ 0		$ 0
Revenue, related party		$ 4,000,000

Related Party Transactions (M_2

Related Party Transactions (Management/Subcontracting agreement) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Line of credit facility, letters of credit issued	$ 153.2	$ 151.8
Subcontracting Arrangements [Member] | Management [Member] | 2019 Acquisitions [Member]
Related Party Transaction [Line Items]
Receivables, net, related party	0.6	0.4
Charges, related party	0.2
Subcontracting Arrangements [Member] | Management [Member] | 2019 Acquisitions [Member] | Line of Credit [Member]
Related Party Transaction [Line Items]
Line of credit facility, letters of credit issued	$ 15
Community Condotte DeMoya JV, LLC [Member]
Related Party Transaction [Line Items]
Equity method investments, ownership percentage	25.00%
Negative equity method investment	$ (2)	(2)
Community Condotte DeMoya JV, LLC [Member] | Subcontracting Arrangements [Member] | Management [Member]
Related Party Transaction [Line Items]
Receivables, net, related party	$ 1.9	$ 1.9

Related Party Transactions (Spl

Related Party Transactions (Split Dollar Agreements) (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Chairman, Board of Directors [Member]
Related Party Transaction [Line Items]
Payments for life insurance policies		$ 0
Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Payments for life insurance policies	$ 0
Executive Officers [Member]
Related Party Transaction [Line Items]
Life insurance assets, carrying amount	$ 22,200,000		$ 22,200,000