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