Earnings Per Share (Schedule Of Earnings Per Share, Basic and Diluted) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Net Income (Loss) Available to Common Stockholders, Basic
Net income from continuing operations before non-controlling interests, basic	$ 36,098		$ 30,827		$ 78,957		$ 90,473
Net income (loss) from discontinued operations before non-controlling interests	(9,277)		1,015		(7,872)		6,969
Net income attributable to MasTec, Inc.	26,821		31,842		71,085		97,442
Weighted Average Number of Shares Outstanding, Basic
Weighted average shares outstanding	76,194	[1]	84,732	[1]	79,009	[1]	81,982	[1]
Earnings (Loss) Per Share, Basic
Basic earnings per share, continuing operations	$ 0.47		$ 0.36		$ 1.00		$ 1.10
Basic earnings per share, discontinued operations	$ (0.12)		$ 0.01		$ (0.10)		$ 0.09
Total basic earnings per share	$ 0.35	[1]	$ 0.38	[1]	$ 0.90	[1]	$ 1.19
Net Income (Loss) Available to Common Stockholders, Diluted
Net income from continuing operations before non-controlling interests, basic	36,098		30,827		78,957		90,473
Diluted net income from continuing operations before non-controlling interests	36,176		30,909		79,191		90,879
Net income (loss) from discontinued operations before non-controlling interests	(9,277)		1,015		(7,872)		6,969
Diluted net income attributable to MasTec	26,899		31,924		71,319		97,848
Weighted Average Number of Shares Outstanding, Diluted
Basic weighted average shares outstanding	76,194	[1]	84,732	[1]	79,009	[1]	81,982	[1]
Dilutive common stock equivalents	887		1,049		842		1,207
Diluted weighted average shares outstanding	79,526	[1]	89,324	[1]	81,982	[1]	86,933	[1]
Earnings (Loss) Per Share, Diluted
Diluted earnings per share, continuing operations	$ 0.45		$ 0.35		$ 0.97		$ 1.05
Diluted earnings per share, discontinued operations	$ (0.12)		$ 0.01		$ (0.10)		$ 0.08
Total diluted earnings per share	$ 0.34	[1]	$ 0.36	[1]	$ 0.87	[1]	$ 1.13	[1]
Convertible Debt [Member] | Original 4.0% Notes [Member]
Net Income (Loss) Available to Common Stockholders, Diluted
Interest expense on convertible debt, net of tax	59		62		176		272
Weighted Average Number of Shares Outstanding, Diluted
Dilutive shares	612		612		612		945
Convertible Debt [Member] | Original 4.25% Notes [Member]
Net Income (Loss) Available to Common Stockholders, Diluted
Interest expense on convertible debt, net of tax	$ 19		$ 20		$ 58		$ 134
Weighted Average Number of Shares Outstanding, Diluted
Dilutive shares	194		194		194		446
Convertible Debt [Member] | New 4.0% Notes [Member]
Weighted Average Number of Shares Outstanding, Diluted
Dilutive premium shares	794		1,366		631		1,166
Convertible Debt [Member] | New 4.25% Notes [Member]
Weighted Average Number of Shares Outstanding, Diluted
Dilutive premium shares	845		1,371		694		1,187

[1] Note that earnings per share tables may contain slight summation differences due to rounding.