Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets
Total current assets	$ 1,422,427	$ 1,129,758
Property and equipment, net	554,513	558,667
Goodwill and other intangible assets, net	1,183,700	1,187,900
Investments in and advances to consolidated affiliates, net	0	0
Other long-term assets	53,392	51,032
Total assets	3,214,046	2,927,347
Liabilities and equity
Total current liabilities	942,365	752,535
Long-term debt	950,641	932,868
Advances from consolidated affiliates, net	0
Other long-term liabilities	291,500	298,500
Total liabilities	2,184,466	1,983,956
Total equity	1,029,580	943,391
Total liabilities and equity	3,214,046	2,927,347
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Assets
Total current assets	0	0
Property and equipment, net	0	0
Goodwill and other intangible assets, net	0	0
Investments in and advances to consolidated affiliates, net	1,012,200	930,300
Other long-term assets	12,600	9,300
Total assets	1,024,800	939,600
Liabilities and equity
Total current liabilities	0	0
Long-term debt	0	0
Advances from consolidated affiliates, net	0
Other long-term liabilities	0	0
Total liabilities	0	0
Total equity	1,024,800	939,600
Total liabilities and equity	1,024,800	939,600
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Assets
Total current assets	1,265,900	927,400
Property and equipment, net	459,000	448,200
Goodwill and other intangible assets, net	1,041,600	1,047,400
Investments in and advances to consolidated affiliates, net	510,200	103,700
Other long-term assets	25,200	24,400
Total assets	3,301,900	2,551,100
Liabilities and equity
Total current liabilities	830,300	632,900
Long-term debt	925,500	900,100
Advances from consolidated affiliates, net	0
Other long-term liabilities	240,500	275,600
Total liabilities	1,996,300	1,808,600
Total equity	1,305,600	742,500
Total liabilities and equity	3,301,900	2,551,100
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Assets
Total current assets	162,300	202,400
Property and equipment, net	95,500	110,500
Goodwill and other intangible assets, net	142,100	140,500
Investments in and advances to consolidated affiliates, net	0	50,600
Other long-term assets	15,600	17,300
Total assets	415,500	521,300
Liabilities and equity
Total current liabilities	117,900	119,600
Long-term debt	25,100	32,800
Advances from consolidated affiliates, net	4,000
Other long-term liabilities	51,000	23,000
Total liabilities	198,000	175,400
Total equity	217,500	345,900
Total liabilities and equity	415,500	521,300
Eliminations [Member]
Assets
Total current assets	(5,800)	0
Property and equipment, net	0	0
Goodwill and other intangible assets, net	0	0
Investments in and advances to consolidated affiliates, net	(1,522,400)	(1,084,600)
Other long-term assets	0	0
Total assets	(1,528,200)	(1,084,600)
Liabilities and equity
Total current liabilities	(5,800)	0
Long-term debt	0	0
Advances from consolidated affiliates, net	(4,000)
Other long-term liabilities	0	0
Total liabilities	(9,800)	0
Total equity	(1,518,400)	(1,084,600)
Total liabilities and equity	$ (1,528,200)	$ (1,084,600)