Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	$ 28,488	$ 161,289
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(4,102)	(148)
Capital expenditures	(63,893)	(48,431)
Proceeds from sale of property and equipment	10,163	4,146
Payments for other investments	(2,040)	(65,150)
Net cash used in investing activities	(59,872)	(109,583)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	684,287	844,494
Repayments of credit facilities	(604,640)	(741,302)
Repayments of other borrowings and capital lease obligations	(33,500)	(35,100)
Repurchase of common stock	0	(100,000)
Proceeds from stock-based awards, net of tax withholdings	3,338	1,849
Excess tax benefit from stock-based compensation	1,132	53
Payments of acquisition-related contingent consideration	(14,572)	(39,257)
Payments of financing costs	0	(1,053)
Net financing activities and advances from (to) consolidated affiliates	0	0
Net cash provided by (used in) financing activities	36,046	(70,368)
Effect of currency translation on cash	(888)	(642)
Net increase (decrease) in cash and cash equivalents	3,774	(19,304)
Cash and cash equivalents - beginning of period	4,984	24,059
Cash and cash equivalents - end of period	8,758	4,755
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	0	(700)
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	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 of tax withholdings	3,300	2,000
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 from (to) consolidated affiliates	(3,300)	98,700
Net cash provided by (used in) financing activities	0	700
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 (used in) provided by operating activities	(30,200)	234,200
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(4,100)	(100)
Capital expenditures	(61,300)	(39,700)
Proceeds from sale of property and equipment	9,100	3,800
Payments for other investments	(500)	(65,200)
Net cash used in investing activities	(56,800)	(101,200)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	625,100	514,600
Repayments of credit facilities	(539,100)	(437,000)
Repayments of other borrowings and capital lease obligations	(25,500)	(25,000)
Repurchase of common stock		0
Proceeds from stock-based awards, net of tax withholdings	(300)	(200)
Excess tax benefit from stock-based compensation	0	100
Payments of acquisition-related contingent consideration	(14,600)	(39,300)
Payments of financing costs		(1,100)
Net financing activities and advances from (to) consolidated affiliates	37,200	(161,200)
Net cash provided by (used in) financing activities	82,800	(149,100)
Effect of currency translation on cash	0	0
Net increase (decrease) in cash and cash equivalents	(4,200)	(16,100)
Cash and cash equivalents - beginning of period	0	18,500
Cash and cash equivalents - end of period	(4,200)	2,400
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	58,700	(72,200)
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0
Capital expenditures	(2,600)	(8,700)
Proceeds from sale of property and equipment	1,000	300
Payments for other investments	(1,500)	0
Net cash used in investing activities	(3,100)	(8,400)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	59,200	329,900
Repayments of credit facilities	(65,500)	(304,300)
Repayments of other borrowings and capital lease obligations	(8,000)	(10,100)
Repurchase of common stock		0
Proceeds from stock-based awards, net of tax withholdings	300	0
Excess tax benefit from stock-based compensation	1,100	0
Payments of acquisition-related contingent consideration	0	0
Payments of financing costs		0
Net financing activities and advances from (to) consolidated affiliates	(33,900)	62,500
Net cash provided by (used in) financing activities	(46,800)	78,000
Effect of currency translation on cash	(900)	(600)
Net increase (decrease) in cash and cash equivalents	7,900	(3,200)
Cash and cash equivalents - beginning of period	5,000	5,600
Cash and cash equivalents - end of period	12,900	2,400
Eliminations [Member]
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by 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	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 of tax withholdings	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 from (to) consolidated affiliates	0	0
Net cash provided by (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