Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Balance Sheets) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
Assets
Current assets	$ 1,272,242	$ 1,048,530
Current assets of discontinued operations	21,763	18,591
Property and equipment, net	470,544	350,378
Goodwill and other intangible assets, net	1,028,908	963,210	823,300	825,500
Net investments in and advances to (from) consolidated affilliates	0	0
Other assets	41,696	46,513
Long-term assets of discontinued operations	7,516	7,648
Total assets	2,820,906	2,416,279
Liabilities and Shareholders' Equity
Current liabilities	798,608	714,046
Current liabilities of discontinued operations	9,905	10,679
Long-term debt	806,497	546,323
Other liabilities	295,488	293,975
Total liabilities	1,900,593	1,554,344
Total shareholders' equity	920,313	861,935
Total liabilities and shareholders' equity	2,820,906	2,416,279
Segment, Continuing Operations [Member]
Assets
Current assets	1,250,479	1,029,939
Liabilities and Shareholders' Equity
Current liabilities	788,703	703,367
MasTec, Inc. [Member]
Assets
Current assets of discontinued operations	0	0
Property and equipment, net	0	0
Goodwill and other intangible assets, net	0	0
Net investments in and advances to (from) consolidated affilliates	920,150	854,992
Other assets	8,038	7,701
Long-term assets of discontinued operations	0	0
Total assets	928,188	862,693
Liabilities and Shareholders' Equity
Current liabilities of discontinued operations	0	0
Long-term debt	0	0
Other liabilities	0	0
Total liabilities	5	20
Total shareholders' equity	928,183	862,673
Total liabilities and shareholders' equity	928,188	862,693
MasTec, Inc. [Member] | Segment, Continuing Operations [Member]
Assets
Current assets	0	0
Liabilities and Shareholders' Equity
Current liabilities	5	20
Guarantor Subsidiaries [Member]
Assets
Current assets of discontinued operations	13,409	13,836
Property and equipment, net	418,501	338,997
Goodwill and other intangible assets, net	925,104	932,481
Net investments in and advances to (from) consolidated affilliates	199,447	172,348
Other assets	33,545	38,732
Long-term assets of discontinued operations	4,517	4,711
Total assets	2,692,035	2,482,671
Liabilities and Shareholders' Equity
Current liabilities of discontinued operations	5,775	6,498
Long-term debt	780,103	546,262
Other liabilities	248,272	273,199
Total liabilities	1,784,171	1,506,495
Total shareholders' equity	907,864	976,176
Total liabilities and shareholders' equity	2,692,035	2,482,671
Guarantor Subsidiaries [Member] | Segment, Continuing Operations [Member]
Assets
Current assets	1,097,512	981,566
Liabilities and Shareholders' Equity
Current liabilities	750,021	680,536
Non-Guarantor Subsidiaries [Member]
Assets
Current assets of discontinued operations	8,354	4,755
Property and equipment, net	52,043	11,381
Goodwill and other intangible assets, net	103,804	30,729
Net investments in and advances to (from) consolidated affilliates	(53,383)	(21,592)
Other assets	113	80
Long-term assets of discontinued operations	2,999	2,937
Total assets	266,897	76,663
Liabilities and Shareholders' Equity
Current liabilities of discontinued operations	4,130	4,181
Long-term debt	26,394	61
Other liabilities	47,216	20,776
Total liabilities	116,417	47,829
Total shareholders' equity	150,480	28,834
Total liabilities and shareholders' equity	266,897	76,663
Non-Guarantor Subsidiaries [Member] | Segment, Continuing Operations [Member]
Assets
Current assets	152,967	48,373
Liabilities and Shareholders' Equity
Current liabilities	38,677	22,811
Consolidation, Eliminations [Member]
Assets
Current assets of discontinued operations	0	0
Property and equipment, net	0	0
Goodwill and other intangible assets, net	0	0
Net investments in and advances to (from) consolidated affilliates	(1,066,214)	(1,005,748)
Other assets	0	0
Long-term assets of discontinued operations	0	0
Total assets	(1,066,214)	(1,005,748)
Liabilities and Shareholders' Equity
Current liabilities of discontinued operations	0	0
Long-term debt	0	0
Other liabilities	0	0
Total liabilities	0	0
Total shareholders' equity	(1,066,214)	(1,005,748)
Total liabilities and shareholders' equity	(1,066,214)	(1,005,748)
Consolidation, Eliminations [Member] | Segment, Continuing Operations [Member]
Assets
Current assets	0	0
Liabilities and Shareholders' Equity
Current liabilities	$ 0	$ 0