Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	$ 118,826	$ (20,394)
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(148)	(23,831)
Capital expenditures	(19,660)	(35,554)
Proceeds from sale of property and equipment	1,360	3,373
Payments for investments, net	(31,959)	(1,098)
Net cash used in investing activities	(50,407)	(57,110)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	439,507	233,872
Repayments of credit facilities	(404,776)	(157,349)
Repayments of other borrowings and capital lease obligations	(15,100)	(13,800)
Repurchase of common stock	(83,261)	0
Proceeds from stock-based awards, net of tax withholdings	925	(1,451)
Excess tax benefit from stock-based compensation	0	3,246
Payments of financing costs	0	(218)
Net financing activities and advances (to) from consolidated affiliates	0	0
Net cash (used in) provided by financing activities	(62,830)	64,314
Effect of currency translation on cash	(957)	(476)
Net increase (decrease) in cash and cash equivalents	4,632	(13,666)
Cash and cash equivalents - beginning of period	24,059	22,927
Cash and cash equivalents - end of period	28,691	9,261
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Condensed Unaudited Consolidating Statements of Cash Flows [Line Items]
Net cash (used in) provided by operating activities	(400)	(200)
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 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	(83,300)
Proceeds from stock-based awards, net of tax withholdings	1,100	1,100
Excess tax benefit from stock-based compensation		0
Payments of financing costs		0
Net financing activities and advances (to) from consolidated affiliates	82,600	(900)
Net cash (used in) provided by financing activities	400	200
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	175,900	(17,800)
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(100)	(23,800)
Capital expenditures	(17,900)	(32,400)
Proceeds from sale of property and equipment	1,200	3,100
Payments for investments, net	(32,000)	(1,100)
Net cash used in investing activities	(48,800)	(54,200)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	251,000	233,900
Repayments of credit facilities	(224,700)	(157,300)
Repayments of other borrowings and capital lease obligations	(10,700)	(13,000)
Repurchase of common stock	0
Proceeds from stock-based awards, net of tax withholdings	(200)	(2,600)
Excess tax benefit from stock-based compensation		3,200
Payments of financing costs		(200)
Net financing activities and advances (to) from consolidated affiliates	(135,700)	8,400
Net cash (used in) provided by financing activities	(120,300)	72,400
Effect of currency translation on cash	0	0
Net increase (decrease) in cash and cash equivalents	6,800	400
Cash and cash equivalents - beginning of period	18,500	5,400
Cash and cash equivalents - end of period	25,300	5,800
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	(56,700)	(2,400)
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	0	0
Capital expenditures	(1,800)	(3,200)
Proceeds from sale of property and equipment	200	300
Payments for investments, net	0	0
Net cash used in investing activities	(1,600)	(2,900)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities	188,500	0
Repayments of credit facilities	(180,100)	0
Repayments of other borrowings and capital lease obligations	(4,400)	(800)
Repurchase of common stock	0
Proceeds from stock-based awards, net of tax withholdings	0	0
Excess tax benefit from stock-based compensation		0
Payments of financing costs		0
Net financing activities and advances (to) from consolidated affiliates	53,100	(7,500)
Net cash (used in) provided by financing activities	57,100	(8,300)
Effect of currency translation on cash	(1,000)	(500)
Net increase (decrease) in cash and cash equivalents	(2,200)	(14,100)
Cash and cash equivalents - beginning of period	5,600	17,600
Cash and cash equivalents - end of period	3,400	3,500
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 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 of tax withholdings	0	0
Excess tax benefit from stock-based compensation		0
Payments of financing costs		0
Net financing activities and advances (to) from consolidated affiliates	0	0
Net cash (used in) provided by 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