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																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Net Income (Loss) Available to Common Stockholders, Basic
Net income from continuing operations																	$ 116,639		$ 97,454		$ 66,166
Net income (loss) from discontinued operations																	(9,213)		8,547		24,362
Net income attributable to MasTec, Inc.	36,300		26,800		30,100		14,200		8,600		31,800		44,500		21,100		107,426		106,001		90,528
Weighted Average Number of Shares Outstanding, Basic
Weighted average shares outstanding																	78,275		82,182		76,132
Earnings (Loss) Per Share, Basic
Basic earnings per share, continuing operations	$ 0.50	[1]	$ 0.47	[1]	$ 0.39	[1]	$ 0.15	[1]	$ 0.08	[1]	$ 0.36	[1]	$ 0.52	[1]	$ 0.21	[1]	$ 1.49		$ 1.19		$ 0.87
Basic earnings per share, discontinued operations	$ (0.02)	[1]	$ (0.12)	[1]	$ (0.01)	[1]	$ 0.03	[1]	$ 0.02	[1]	$ 0.01	[1]	$ 0.01	[1]	$ 0.06	[1]	$ (0.12)		$ 0.10		$ 0.32
Total basic earnings per share	$ 0.48	[1]	$ 0.35	[1]	$ 0.37	[1]	$ 0.18	[1]	$ 0.10	[1]	$ 0.37	[1]	$ 0.53	[1]	$ 0.27	[1]	$ 1.37	[2]	$ 1.29	[2]	$ 1.19	[2]
Net Income (Loss) Available to Common Stockholders, Diluted
Net income from continuing operations																	116,639		97,454		66,166
Diluted net income from continuing operations																	116,950		97,939		71,297
Net income (loss) from discontinued operations																	(9,213)		8,547		24,362
Diluted net income attributable to MasTec																	107,737		106,486		95,659
Weighted Average Number of Shares Outstanding, Diluted
Weighted average shares outstanding																	78,275		82,182		76,132
Dilutive common stock equivalents																	888		1,127		994
Diluted weighted average shares outstanding																	82,087		86,716		90,885
Earnings (Loss) Per Share, Diluted
Diluted earnings per share, continuing operations	$ 0.46	[1]	$ 0.45	[1]	$ 0.38	[1]	$ 0.14	[1]	$ 0.08	[1]	$ 0.35	[1]	$ 0.50	[1]	$ 0.20	[1]	$ 1.42		$ 1.13		$ 0.78
Diluted earnings per share, discontinued operations	$ (0.02)	[1]	$ (0.12)	[1]	$ (0.01)	[1]	$ 0.03	[1]	$ 0.02	[1]	$ 0.01	[1]	$ 0.01	[1]	$ 0.06	[1]	$ (0.11)		$ 0.10		$ 0.27
Total diluted earnings per share	$ 0.45	[1]	$ 0.34	[1]	$ 0.37	[1]	$ 0.17	[1]	$ 0.10	[1]	$ 0.36	[1]	$ 0.51	[1]	$ 0.26	[1]	$ 1.31	[2]	$ 1.23	[2]	$ 1.05	[2]
Convertible Debt [Member] | Original 4.0% Notes [Member]
Net Income (Loss) Available to Common Stockholders, Diluted
Interest expense on convertible debt, net of tax																	234		331		2,667
Weighted Average Number of Shares Outstanding, Diluted
Dilutive shares																	612		862		7,297
Convertible Debt [Member] | Original 4.25% Notes [Member]
Net Income (Loss) Available to Common Stockholders, Diluted
Interest expense on convertible debt, net of tax																	$ 77		$ 154		$ 2,464
Weighted Average Number of Shares Outstanding, Diluted
Dilutive shares																	194		383		6,462
Convertible Debt [Member] | New 4.0% Notes [Member]
Weighted Average Number of Shares Outstanding, Diluted
Dilutive premium shares																	1,044		1,067		0
Convertible Debt [Member] | New 4.25% Notes [Member]
Weighted Average Number of Shares Outstanding, Diluted
Dilutive premium shares																	1,074		1,095		0

[1] Note that due to rounding differences, the sum of the Company’s quarterly earnings per share in a given year may not be the same as the Company’s year to date earnings per share for the same period. In addition, earnings per share calculations may contain slight summation differences due to rounding. See Note 2 – Earnings per Share.

[2] Earnings per share tables may contain slight summation differences due to rounding