Earnings Per Share (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net income attributable to MasTec:
Net income - basic	$ 111,087	$ 116,491	$ 252,187	$ 209,726
Net income - diluted	$ 111,087	$ 116,491	$ 252,187	$ 209,726
Weighted average shares outstanding:
Weighted average shares outstanding - basic (in shares)	72,503,000	72,138,000	72,481,000	72,971,000
Dilutive common stock equivalents (in shares)	1,474,000	957,000	1,440,000	816,000
Weighted average shares outstanding - diluted (in shares)	73,977,000	73,095,000	73,921,000	73,787,000
Anti-dilutive common stock (in shares)	9,661	0	109,377	58,759