Condensed Unaudited Consolidated Statements of Equity - 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
Acquisition of treasury stock, at cost (in shares)			(2,000,000.0)
Acquisition of treasury stock, at cost	(98,400)
Ending balance, common shares outstanding (in shares) at Mar. 31, 2018		91,063,699
Ending balance at Mar. 31, 2018	1,374,197	$ 9,106	$ (245,573)	779,449	885,277	(56,519)	1,371,740	2,457
Ending balance, treasury shares (in shares) at Mar. 31, 2018			(10,171,531)
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)	106,864				107,052		107,052	(188)
Other comprehensive (loss) income	8,478					8,478	8,478
Non-cash stock-based compensation	6,571			6,571			6,571
Issuance (forfeiture) of restricted shares, net (in shares)		96,018
Issuance (forfeiture) of restricted shares, net	0	$ 10		(10)			0
Other stock issuances, net of shares withheld for taxes (in shares)		48,678
Other stock issuances, net of shares withheld for taxes	1,881	$ 4		1,877			1,881
Acquisition of treasury stock, at cost (in shares)			(2,702,938)
Acquisition of treasury stock, at cost	(128,311)		$ (128,311)				(128,311)
Ending balance, common shares outstanding (in shares) at Jun. 30, 2018		91,080,280
Ending balance at Jun. 30, 2018	1,430,398	$ 9,108	$ (275,435)	783,825	965,768	(55,234)	1,428,032	2,366
Ending balance, treasury shares (in shares) at Jun. 30, 2018			(10,835,749)
Beginning balance, common shares outstanding (in shares) at Mar. 31, 2018		91,063,699
Beginning balance at Mar. 31, 2018	1,374,197	$ 9,106	$ (245,573)	779,449	885,277	(56,519)	1,371,740	2,457
Beginning balance, treasury shares (in shares) at Mar. 31, 2018			(10,171,531)
Condensed Unaudited Consolidated Statements of Equity
Net income (loss)	80,401				80,492		80,492	(91)
Other comprehensive (loss) income	1,285					1,285	1,285
Non-cash stock-based compensation	3,389			3,389			3,389
Issuance (forfeiture) of restricted shares, net (in shares)		(8,797)
Issuance (forfeiture) of restricted shares, net	0	$ (1)		1			0
Other stock issuances, net of shares withheld for taxes (in shares)		25,378
Other stock issuances, net of shares withheld for taxes	989	$ 3		986			989
Acquisition of treasury stock, at cost (in shares)			(664,218)
Acquisition of treasury stock, at cost	(29,862)		$ (29,862)				(29,862)
Ending balance, common shares outstanding (in shares) at Jun. 30, 2018		91,080,280
Ending balance at Jun. 30, 2018	$ 1,430,398	$ 9,108	$ (275,435)	783,825	965,768	(55,234)	1,428,032	2,366
Ending balance, treasury shares (in shares) at Jun. 30, 2018			(10,835,749)
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)	$ 163,330				162,823		162,823	507
Other comprehensive (loss) income	(14,181)					(14,181)	(14,181)
Non-cash stock-based compensation	7,940			7,940			7,940
Issuance (forfeiture) of restricted shares, net (in shares)		233,419
Issuance (forfeiture) of restricted shares, net	0	$ 23		(23)			0
Other stock issuances, net of shares withheld for taxes (in shares)		66,558
Other stock issuances, net of shares withheld for taxes	2,243	$ 7		2,236			2,243
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 Jun. 30, 2019	91,626,986	91,626,986
Ending balance at Jun. 30, 2019	$ 1,551,338	$ 9,163	$ (466,727)	799,162	1,281,198	(74,675)	1,548,121	3,217
Ending balance, treasury shares (in shares) at Jun. 30, 2019	(15,344,917)		(15,344,917)
Beginning balance, common shares outstanding (in shares) at Mar. 31, 2019		91,591,398
Beginning balance at Mar. 31, 2019	$ 1,433,732	$ 9,159	$ (466,727)	793,748	1,161,487	(66,056)	1,431,611	2,121
Beginning balance, treasury shares (in shares) at Mar. 31, 2019			(15,344,917)
Condensed Unaudited Consolidated Statements of Equity
Net income (loss)	120,223				119,710		119,710	513
Other comprehensive (loss) income	(8,619)					(8,619)	(8,619)
Non-cash stock-based compensation	4,220			4,220			4,220
Issuance (forfeiture) of restricted shares, net (in shares)		57
Issuance (forfeiture) of restricted shares, net	0	$ 0		0			0
Other stock issuances, net of shares withheld for taxes (in shares)		35,531
Other stock issuances, net of shares withheld for taxes	1,198	$ 4		1,194			1,198
Acquisition of treasury stock, at cost (in shares)			0
Contributions from non-controlling interests	$ 584						0	584
Ending balance, common shares outstanding (in shares) at Jun. 30, 2019	91,626,986	91,626,986
Ending balance at Jun. 30, 2019	$ 1,551,338	$ 9,163	$ (466,727)	$ 799,162	$ 1,281,198	$ (74,675)	$ 1,548,121	$ 3,217
Ending balance, treasury shares (in shares) at Jun. 30, 2019	(15,344,917)		(15,344,917)