Earnings Per Share (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net income attributable to MasTec:
Net income - basic	$ 75,451	$ 57,005	$ 141,100	$ 93,235
Net income - diluted	$ 75,451	$ 57,005	$ 141,100	$ 93,235
Weighted average shares outstanding:
Weighted average shares outstanding - basic (in shares)	72,501,000	72,045,000	72,470,000	73,392,000
Dilutive common stock equivalents (in shares)	1,475,000	732,000	1,443,000	743,000
Weighted average shares outstanding - diluted (in shares)	73,976,000	72,777,000	73,913,000	74,135,000
Anti-dilutive common stock (in shares)			2,166	88,462