Earnings Per Share (Schedule of Earnings Per Share Information) (Details) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
		Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income attributable to MasTec:
Net income, continuing operations - basic (in dollars)	[1]						$ 122,375	$ 147,492	$ 116,639
Net income attributable to MasTec - diluted (in dollars)							116,104	141,265	107,737
Net loss from discontinued operations - basic and diluted (in dollars)	[1]						$ (6,452)	$ (6,542)	$ (9,213)
Weighted average shares outstanding:
Weighted average shares outstanding - basic		81,811	78,269	77,345	77,810	79,158	79,953	76,923	78,275
Dilutive common stock equivalents (in shares)							813	777	883
Weighted average shares outstanding - diluted		85,824	86,730	86,622	86,675	86,416	86,196	84,901	82,082
Continuing Operations [Member]
Net income attributable to MasTec:
Net income attributable to MasTec - diluted (in dollars)							$ 122,556	$ 147,807	$ 116,950
2009 Convertible Notes [Member]
Net income attributable to MasTec:
Interest expense, net of tax, 2009 Convertible Notes (in dollars)							$ 181	$ 315	$ 311
Weighted average shares outstanding:
Dilutive shares, 2009 Convertible Notes							459	806	806
2011 Convertible Notes [Member] | Convertible Debt [Member]
Weighted average shares outstanding:
Dilutive premium shares, 2011 Convertible Notes							4,971	6,395	2,118

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