Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	$ 127,141	$ 260,602
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(4,102)	(148)
Capital expenditures	(89,050)	(70,766)
Proceeds from sale of property and equipment	6,824	9,763
Payments for other investments, net	(7,733)	(109,299)
Net cash used in investing activities	(94,061)	(170,450)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	1,186,816	1,329,610
Repayments of credit facilities	(1,149,930)	(1,240,122)
Repayments of other borrowings and capital lease obligations	(50,000)	(51,300)
Repurchase of common stock	0	(100,000)
Proceeds from stock-based awards, net	3,938	1,743
Excess tax benefit from stock-based compensation	1,385	56
Payments of acquisition-related contingent consideration	(19,822)	(44,757)
Payments of financing costs	0	(2,435)
Net financing activities and advances (to) from consolidated affiliates	0	0
Net cash used in financing activities	(27,629)	(107,160)
Effect of currency translation on cash	(1,008)	103
Net increase (decrease) in cash and cash equivalents	4,443	(16,905)
Cash and cash equivalents - beginning of period	4,984	24,059
Cash and cash equivalents - end of period	9,427	7,154
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	0	(1,100)
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0
Capital expenditures	0	0
Proceeds from sale of property and equipment	0	0
Payments for other investments, net	0	0
Net cash used in investing activities	0	0
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	0	0
Repayments of credit facilities	0	0
Repayments of other borrowings and capital lease obligations	0	0
Repurchase of common stock		(100,000)
Proceeds from stock-based awards, net	3,400	2,100
Excess tax benefit from stock-based compensation	1,400	0
Payments of acquisition-related contingent consideration	0	0
Payments of financing costs		0
Net financing activities and advances (to) from consolidated affiliates	(4,800)	99,000
Net cash used in financing activities	0	1,100
Effect of currency translation on cash	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents - beginning of period	0	0
Cash and cash equivalents - end of period	0	0
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	87,200	317,000
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(4,100)	(100)
Capital expenditures	(84,000)	(58,200)
Proceeds from sale of property and equipment	3,100	8,400
Payments for other investments, net	(3,800)	(109,300)
Net cash used in investing activities	(88,800)	(159,200)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	1,093,800	827,100
Repayments of credit facilities	(1,056,100)	(747,800)
Repayments of other borrowings and capital lease obligations	(37,600)	(36,400)
Repurchase of common stock		0
Proceeds from stock-based awards, net	0	(400)
Excess tax benefit from stock-based compensation	0	100
Payments of acquisition-related contingent consideration	(16,500)	(37,300)
Payments of financing costs		(2,400)
Net financing activities and advances (to) from consolidated affiliates	15,100	(169,200)
Net cash used in financing activities	(1,300)	(166,300)
Effect of currency translation on cash	0	0
Net increase (decrease) in cash and cash equivalents	(2,900)	(8,500)
Cash and cash equivalents - beginning of period	4,700	18,500
Cash and cash equivalents - end of period	1,800	10,000
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	39,900	(55,300)
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0
Capital expenditures	(5,100)	(12,600)
Proceeds from sale of property and equipment	3,700	1,400
Payments for other investments, net	(3,900)	0
Net cash used in investing activities	(5,300)	(11,200)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	93,000	502,500
Repayments of credit facilities	(93,800)	(492,300)
Repayments of other borrowings and capital lease obligations	(12,400)	(14,900)
Repurchase of common stock		0
Proceeds from stock-based awards, net	500	0
Excess tax benefit from stock-based compensation	0	0
Payments of acquisition-related contingent consideration	(3,300)	(7,500)
Payments of financing costs		0
Net financing activities and advances (to) from consolidated affiliates	(10,300)	70,200
Net cash used in financing activities	(26,300)	58,000
Effect of currency translation on cash	(1,000)	100
Net increase (decrease) in cash and cash equivalents	7,300	(8,400)
Cash and cash equivalents - beginning of period	300	5,600
Cash and cash equivalents - end of period	7,600	(2,800)
Eliminations [Member]
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	0	0
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0
Capital expenditures	0	0
Proceeds from sale of property and equipment	0	0
Payments for other investments, net	0	0
Net cash used in investing activities	0	0
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	0	0
Repayments of credit facilities	0	0
Repayments of other borrowings and capital lease obligations	0	0
Repurchase of common stock		0
Proceeds from stock-based awards, net	0	0
Excess tax benefit from stock-based compensation	0	0
Payments of acquisition-related contingent consideration	0	0
Payments of financing costs		0
Net financing activities and advances (to) from consolidated affiliates	0	0
Net cash used in financing activities	0	0
Effect of currency translation on cash	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents - beginning of period	0	0
Cash and cash equivalents - end of period	$ 0	$ 0