Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Balance Sheets) (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Assets
Current assets	$ 1,145,749	$ 1,047,365
Current assets of discontinued operations	20,091	18,591
Property and equipment, net	383,174	350,378
Goodwill and other intangible assets, net	956,899	961,807	822,700	825,500
Net investments in and advances to (from) consolidated affilliates	0	0
Other assets	47,374	45,421
Long-term assets of discontinued operations	7,670	7,648
Total assets	2,540,866	2,412,619
Liabilities and Shareholders' Equity
Current liabilities	691,729	710,386
Current liabilities of discontinued operations	2,508	4,569
Long-term debt	685,390	546,323
Other liabilities	278,092	293,975
Total liabilities	1,655,211	1,550,684
Total shareholders' equity	885,655	861,935
Total liabilities and shareholders' equity	2,540,866	2,412,619
Segment, Continuing Operations [Member]
Assets
Current assets	1,125,658	1,028,774
Liabilities and Shareholders' Equity
Current liabilities	689,221	705,817
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	878,886	854,993
Other assets	8,112	7,702
Long-term assets of discontinued operations	0	0
Total assets	886,998	862,695
Liabilities and Shareholders' Equity
Current liabilities of discontinued operations	0	0
Long-term debt	0	0
Other liabilities	0	0
Total liabilities	5	22
Total shareholders' equity	886,993	862,673
Total liabilities and shareholders' equity	886,998	862,695
MasTec, Inc. [Member] | Segment, Continuing Operations [Member]
Assets
Current assets	0	0
Liabilities and Shareholders' Equity
Current liabilities	5	22
Guarantor Subsidiaries [Member]
Assets
Current assets of discontinued operations	13,204	13,836
Property and equipment, net	372,492	338,997
Goodwill and other intangible assets, net	927,086	931,078
Net investments in and advances to (from) consolidated affilliates	205,786	172,534
Other assets	39,192	37,639
Long-term assets of discontinued operations	4,711	4,711
Total assets	2,609,931	2,479,196
Liabilities and Shareholders' Equity
Current liabilities of discontinued operations	0	574
Long-term debt	685,340	546,262
Other liabilities	262,122	273,199
Total liabilities	1,613,998	1,503,020
Total shareholders' equity	995,933	976,176
Total liabilities and shareholders' equity	2,609,931	2,479,196
Guarantor Subsidiaries [Member] | Segment, Continuing Operations [Member]
Assets
Current assets	1,047,460	980,401
Liabilities and Shareholders' Equity
Current liabilities	666,536	682,985
Non-Guarantor Subsidiaries [Member]
Assets
Current assets of discontinued operations	6,887	4,755
Property and equipment, net	10,682	11,381
Goodwill and other intangible assets, net	29,813	30,729
Net investments in and advances to (from) consolidated affilliates	(54,307)	(21,779)
Other assets	70	80
Long-term assets of discontinued operations	2,959	2,937
Total assets	74,302	76,476
Liabilities and Shareholders' Equity
Current liabilities of discontinued operations	2,508	3,995
Long-term debt	50	61
Other liabilities	15,970	20,776
Total liabilities	41,208	47,642
Total shareholders' equity	33,094	28,834
Total liabilities and shareholders' equity	74,302	76,476
Non-Guarantor Subsidiaries [Member] | Segment, Continuing Operations [Member]
Assets
Current assets	78,198	48,373
Liabilities and Shareholders' Equity
Current liabilities	22,680	22,810
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	(1,030,365)	(1,005,748)
Other assets	0	0
Long-term assets of discontinued operations	0	0
Total assets	(1,030,365)	(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	(1,030,365)	(1,005,748)
Total liabilities and shareholders' equity	(1,030,365)	(1,005,748)
Consolidation, Eliminations [Member] | Segment, Continuing Operations [Member]
Assets
Current assets	0	0
Liabilities and Shareholders' Equity
Current liabilities	$ 0	$ 0