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]
Condensed Unaudited Consolidated Statements of Equity
Cumulative effect of adoption, Topic 606	$ 1,562				$ 1,562		$ 1,562
Beginning balance, common shares outstanding (in shares) at Dec. 31, 2017		90,935,584
Beginning balance at Dec. 31, 2017	1,433,353	$ 9,094	$ (147,124)	$ 775,387	857,154	$ (63,712)	1,430,799	$ 2,554
Beginning balance, treasury shares (in shares) at Dec. 31, 2017			(8,132,811)
Condensed Unaudited Consolidated Statements of Equity
Net income (loss)	227,406				227,718		227,718	(312)
Other comprehensive income (loss)	12,845					12,845	12,845
Non-cash stock-based compensation	10,086			10,086			10,086
Issuance (forfeiture) of restricted shares, net (in shares)		90,807
Issuance (forfeiture) of restricted shares, net	0	$ 9		(9)			0
Other stock issuances, net of shares withheld for taxes (in shares)		77,680
Other stock issuances, net of shares withheld for taxes	$ 3,016	$ 7		3,009			3,016
Acquisition of treasury stock, at cost (in shares)	(4,300,000)		(4,307,297)
Acquisition of treasury stock, at cost	$ (198,448)		$ (198,448)				(198,448)
Ending balance, common shares outstanding (in shares) at Sep. 30, 2018		91,104,071
Ending balance at Sep. 30, 2018	1,489,820	$ 9,110	$ (345,572)	788,473	1,086,434	(50,867)	1,487,578	2,242
Ending balance, treasury shares (in shares) at Sep. 30, 2018			(12,440,108)
Beginning balance, common shares outstanding (in shares) at Jun. 30, 2018		91,080,280
Beginning balance at Jun. 30, 2018	1,430,398	$ 9,108	$ (275,435)	783,825	965,768	(55,234)	1,428,032	2,366
Beginning balance, treasury shares (in shares) at Jun. 30, 2018			(10,835,749)
Condensed Unaudited Consolidated Statements of Equity
Net income (loss)	120,542				120,666		120,666	(124)
Other comprehensive income (loss)	4,367					4,367	4,367
Non-cash stock-based compensation	3,515			3,515			3,515
Issuance (forfeiture) of restricted shares, net (in shares)		(5,211)
Issuance (forfeiture) of restricted shares, net	0	$ (1)		1			0
Other stock issuances, net of shares withheld for taxes (in shares)		29,002
Other stock issuances, net of shares withheld for taxes	$ 1,135	$ 3		1,132			1,135
Acquisition of treasury stock, at cost (in shares)	(1,600,000)		(1,604,359)
Acquisition of treasury stock, at cost	$ (70,137)		$ (70,137)				(70,137)
Ending balance, common shares outstanding (in shares) at Sep. 30, 2018		91,104,071
Ending balance at Sep. 30, 2018	$ 1,489,820	$ 9,110	$ (345,572)	788,473	1,086,434	(50,867)	1,487,578	2,242
Ending balance, treasury shares (in shares) at Sep. 30, 2018			(12,440,108)
Beginning balance, common shares outstanding (in shares) at Dec. 31, 2018	91,327,009	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)		(15,329,817)
Condensed Unaudited Consolidated Statements of Equity
Net income (loss)	$ 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 (forfeiture) of restricted shares, net (in shares)		232,499
Issuance (forfeiture) 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 non-controlling interests	$ 584						0	584
Ending balance, common shares outstanding (in shares) at Sep. 30, 2019	91,654,158	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)		(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 (loss)	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 (forfeiture) of restricted shares, net (in shares)		(920)
Issuance (forfeiture) 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
Acquisition of treasury stock, at cost (in shares)	0
Ending balance, common shares outstanding (in shares) at Sep. 30, 2019	91,654,158	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)		(15,344,917)