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