Earnings Per Share (Schedule of Earnings Per Share Information) (Details) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Net income (loss) attributable to MasTec:
Net income (loss) - basic (in dollars)		$ 160,800	$ 63,800	$ 81,700	$ 41,000	$ 53,600	$ 56,300	$ 24,100	$ (2,700)	$ 347,213	[1]	$ 131,263	[1]	$ (79,110)	[1]
Net income (loss) - diluted (in dollars)										$ 347,213		$ 131,263		$ (79,110)
Weighted average shares outstanding:
Weighted average shares outstanding - basic										80,903		80,372		80,489
Dilutive common stock equivalents (in shares)										1,422		1,022		0
Weighted average shares outstanding - diluted										82,325		81,394		80,489
Common Stock [Member]
Additional information:
Weighted average anti-dilutive common stock equivalents (in shares)	[2]									0		31		564

[1] Calculated as total net income (loss) less amounts attributable to non-controlling interests.

[2] For the year ended December 31, 2016, represents anti-dilutive common stock equivalents as calculated under the treasury stock method, and, for the year ended December 31, 2015, represents anti-dilutive common stock equivalents due to the Company having reported a net loss.