Supplemental Guarantor Financial Information (Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Consolidating Statements of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	$ 205,593	$ 367,413	$ 323,011
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(4,102)	(148)	(345,543)
Capital expenditures	(117,114)	(84,410)	(109,254)
Proceeds from sale of property and equipment	11,239	13,932	16,655
Payments for investments, net	(31,000)	(58,100)	(1,100)
Net cash used in investing activities	(141,021)	(128,700)	(439,262)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	1,681,424	1,702,431	2,385,971
Repayments of credit facilities	(1,627,129)	(1,742,077)	(1,939,612)
Repayments of senior convertible notes	0	0	(202,325)
Repayments of other borrowings and capital lease obligations	(68,700)	(70,900)	(67,300)
Repurchase of common stock	0	(100,000)	0
Proceeds from stock-based awards, net	4,200	1,566	1,113
Excess tax benefit from stock-based compensation	135	57	3,728
Payments of acquisition-related contingent consideration	(19,822)	(47,523)	(60,341)
Other financing activities, net	380	(2,436)	(2,572)
Net financing activities and advances (to) from consolidated affiliates	0	0	0
Net cash (used in) provided by financing activities	(29,486)	(258,920)	118,675
Effect of currency translation on cash	(1,303)	1,132	(1,292)
Net increase (decrease) in cash and cash equivalents	33,783	(19,075)	1,132
Cash and cash equivalents - beginning of period	4,984	24,059	22,927
Cash and cash equivalents - end of period	38,767	4,984	24,059
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Condensed Consolidating Statements of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	0	900	(500)
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0	0
Capital expenditures	0	0	0
Proceeds from sale of property and equipment	0	0	0
Payments for investments, net	0	(1,900)	(1,000)
Net cash used in investing activities	0	(1,900)	(1,000)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	0	0	0
Repayments of credit facilities	0	0	0
Repayments of senior convertible notes			0
Repayments of other borrowings and capital lease obligations	0	0	0
Repurchase of common stock		(100,000)
Proceeds from stock-based awards, net	4,200	2,700	3,800
Excess tax benefit from stock-based compensation	100	0	0
Payments of acquisition-related contingent consideration	0	0	0
Other financing activities, net	0	0	0
Net financing activities and advances (to) from consolidated affiliates	(4,300)	98,300	(2,300)
Net cash (used in) provided by financing activities	0	1,000	1,500
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 provided by (used in) operating activities	130,400	358,500	251,900
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(4,100)	(100)	(222,700)
Capital expenditures	(106,200)	(71,900)	(84,800)
Proceeds from sale of property and equipment	7,500	10,500	14,300
Payments for investments, net	(3,900)	0	(100)
Net cash used in investing activities	(106,700)	(61,500)	(293,300)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	1,553,400	1,097,300	1,894,400
Repayments of credit facilities	(1,496,600)	(1,154,300)	(1,410,000)
Repayments of senior convertible notes			(202,300)
Repayments of other borrowings and capital lease obligations	(50,300)	(54,300)	(39,000)
Repurchase of common stock		0
Proceeds from stock-based awards, net	0	(1,100)	(2,700)
Excess tax benefit from stock-based compensation	0	100	3,700
Payments of acquisition-related contingent consideration	(16,600)	(37,300)	(60,300)
Other financing activities, net	(100)	(2,400)	(2,600)
Net financing activities and advances (to) from consolidated affiliates	10,000	(158,700)	(126,700)
Net cash (used in) provided by financing activities	(200)	(310,700)	54,500
Effect of currency translation on cash	0	0	0
Net increase (decrease) in cash and cash equivalents	23,500	(13,700)	13,100
Cash and cash equivalents - beginning of period	4,800	18,500	5,400
Cash and cash equivalents - end of period	28,300	4,800	18,500
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	75,200	8,000	71,600
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0	(122,900)
Capital expenditures	(10,900)	(12,500)	(24,500)
Proceeds from sale of property and equipment	3,700	3,400	2,400
Payments for investments, net	(27,100)	(56,300)	0
Net cash used in investing activities	(34,300)	(65,400)	(145,000)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	128,000	605,100	491,600
Repayments of credit facilities	(130,500)	(587,800)	(529,600)
Repayments of senior convertible notes			0
Repayments of other borrowings and capital lease obligations	(18,400)	(16,600)	(28,300)
Repurchase of common stock		0
Proceeds from stock-based awards, net	0	0	0
Excess tax benefit from stock-based compensation	0	0	0
Payments of acquisition-related contingent consideration	(3,200)	(10,200)	0
Other financing activities, net	500	0	0
Net financing activities and advances (to) from consolidated affiliates	(5,700)	60,400	129,000
Net cash (used in) provided by financing activities	(29,300)	50,900	62,700
Effect of currency translation on cash	(1,300)	1,100	(1,300)
Net increase (decrease) in cash and cash equivalents	10,300	(5,400)	(12,000)
Cash and cash equivalents - beginning of period	200	5,600	17,600
Cash and cash equivalents - end of period	10,500	200	5,600
Eliminations [Member]
Condensed Consolidating Statements of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	0	0	0
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0	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 senior convertible notes			0
Repayments of other borrowings and capital lease obligations	0	0	0
Repurchase of common stock		0
Proceeds from stock-based awards, net	0	0	0
Excess tax benefit from stock-based compensation	0	0	0
Payments of acquisition-related contingent consideration	0	0	0
Other financing activities, net	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