Supplemental Guarantor Financial Information (Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	$ 367,413	$ 323,011	$ 200,402
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(148)	(345,543)	(148,567)
Proceeds from disposal of business, net of cash divested	0	0	(2,997)
Capital expenditures	(84,410)	(109,254)	(126,288)
Proceeds from sale of property and equipment	13,932	16,655	15,858
Payments for investments, net	(58,100)	(1,100)	(1,200)
Net cash used in investing activities	(128,700)	(439,262)	(263,211)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	1,702,431	2,385,971	1,149,040
Repayments of credit facilities	(1,742,077)	(1,939,612)	(1,249,601)
(Repayments of) proceeds from senior notes, net		(202,300)	250,000
Repayments of other borrowings and capital lease obligations	(70,900)	(67,300)	(70,700)
Repurchase of common stock	(100,000)	0	0
Proceeds from stock-based awards, net of tax withholdings	1,566	1,113	8,355
Excess tax benefit from stock-based compensation	57	3,728	4,315
Payments of acquisition-related contingent consideration	(47,523)	(60,341)	(18,683)
Payments of financing costs	(2,436)	(2,572)	(13,688)
Net financing activities and advances (to) from consolidated affiliates	0	0	0
Net cash (used in) provided by financing activities	(258,920)	118,675	58,993
Effect of currency translation on cash	1,132	(1,292)	(24)
Net increase (decrease) in cash and cash equivalents	(19,075)	1,132	(3,840)
Cash and cash equivalents - beginning of period	24,059	22,927	26,767
Cash and cash equivalents - end of period	4,984	24,059	22,927
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Condensed Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	900	(500)	(1,700)
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0	0
Proceeds from disposal of business, net of cash divested			0
Capital expenditures	0	0	0
Proceeds from sale of property and equipment	0	0	0
Payments for investments, net	(1,900)	(1,000)	(1,200)
Net cash used in investing activities	(1,900)	(1,000)	(1,200)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	0	0	0
Repayments of credit facilities	0	0	0
(Repayments of) proceeds from senior notes, net		0	0
Repayments of other borrowings and capital lease obligations	0	0	0
Repurchase of common stock	(100,000)
Proceeds from stock-based awards, net of tax withholdings	2,700	3,800	9,900
Excess tax benefit from stock-based compensation	0	0	0
Payments of acquisition-related contingent consideration	0	0	0
Payments of financing costs	0	0	0
Net financing activities and advances (to) from consolidated affiliates	98,300	(2,300)	(7,000)
Net cash (used in) provided by financing activities	1,000	1,500	2,900
Effect of currency translation on cash	0	0	0
Net increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents - beginning of period	0	0	0
Cash and cash equivalents - end of period	0	0	0
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	426,700	251,900	174,100
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(100)	(222,700)	(45,000)
Proceeds from disposal of business, net of cash divested			(3,000)
Capital expenditures	(71,900)	(84,800)	(114,400)
Proceeds from sale of property and equipment	10,500	14,300	14,700
Payments for investments, net	0	(100)	0
Net cash used in investing activities	(61,500)	(293,300)	(147,700)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	1,097,300	1,894,400	961,600
Repayments of credit facilities	(1,154,400)	(1,410,000)	(1,042,200)
(Repayments of) proceeds from senior notes, net		(202,300)	250,000
Repayments of other borrowings and capital lease obligations	(54,300)	(39,000)	(69,100)
Repurchase of common stock	0
Proceeds from stock-based awards, net of tax withholdings	(1,100)	(2,700)	(1,500)
Excess tax benefit from stock-based compensation	100	3,700	4,300
Payments of acquisition-related contingent consideration	(37,300)	(60,300)	(16,700)
Payments of financing costs	(2,400)	(2,600)	(13,700)
Net financing activities and advances (to) from consolidated affiliates	(226,800)	(126,700)	(106,400)
Net cash (used in) provided by financing activities	(378,900)	54,500	(33,700)
Effect of currency translation on cash	0	0	0
Net increase (decrease) in cash and cash equivalents	(13,700)	13,100	(7,300)
Cash and cash equivalents - beginning of period	18,500	5,400	12,700
Cash and cash equivalents - end of period	4,800	18,500	5,400
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	(60,200)	71,600	28,000
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	(122,900)	(103,600)
Proceeds from disposal of business, net of cash divested			0
Capital expenditures	(12,500)	(24,500)	(11,900)
Proceeds from sale of property and equipment	3,400	2,400	1,200
Payments for investments, net	(56,200)	0	0
Net cash used in investing activities	(65,300)	(145,000)	(114,300)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	605,100	491,600	187,400
Repayments of credit facilities	(587,800)	(529,600)	(207,400)
(Repayments of) proceeds from senior notes, net		0	0
Repayments of other borrowings and capital lease obligations	(16,600)	(28,300)	(1,600)
Repurchase of common stock	0
Proceeds from stock-based awards, net of tax withholdings	0	0	0
Excess tax benefit from stock-based compensation	0	0	0
Payments of acquisition-related contingent consideration	(10,200)	0	(2,000)
Payments of financing costs	0	0	0
Net financing activities and advances (to) from consolidated affiliates	128,500	129,000	113,400
Net cash (used in) provided by financing activities	119,000	62,700	89,800
Effect of currency translation on cash	1,100	(1,300)	0
Net increase (decrease) in cash and cash equivalents	(5,400)	(12,000)	3,500
Cash and cash equivalents - beginning of period	5,600	17,600	14,100
Cash and cash equivalents - end of period	200	5,600	17,600
Eliminations [Member]
Condensed Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	0	0	0
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0	0
Proceeds from disposal of business, net of cash divested			0
Capital expenditures	0	0	0
Proceeds from sale of property and equipment	0	0	0
Payments for investments, net	0	0	0
Net cash used in investing activities	0	0	0
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	0	0	0
Repayments of credit facilities	0	0	0
(Repayments of) proceeds from senior notes, net		0	0
Repayments of other borrowings and capital lease obligations	0	0	0
Repurchase of common stock	0
Proceeds from stock-based awards, net of tax withholdings	0	0	0
Excess tax benefit from stock-based compensation	0	0	0
Payments of acquisition-related contingent consideration	0	0	0
Payments of financing costs	0	0	0
Net financing activities and advances (to) from consolidated affiliates	0	0	0
Net cash (used in) provided by financing activities	0	0	0
Effect of currency translation on cash	0	0	0
Net increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents - beginning of period	0	0	0
Cash and cash equivalents - end of period	$ 0	$ 0	$ 0