Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		$ 1,158,184	$ 974,225
Costs of revenue, excluding depreciation and amortization		971,134	884,401
Depreciation and amortization		42,904	39,008
General and administrative expenses		64,781	60,048
Interest expense (income), net		12,597	12,158
Equity in (earnings) losses of unconsolidated affiliates		(1,646)	(3,066)
Other expense (income), net		429	(13,356)
Income (loss) before income taxes		67,985	(4,968)
(Provision for) benefit from income taxes		(27,358)	2,087
Net (loss) income before equity in income from subsidiaries		40,600	(2,900)
Equity in income (losses) from subsidiaries, net of tax		0	0
Net income (loss)		40,627	(2,881)
Net loss attributable to non-controlling interests		(343)	(189)
Net income (loss) attributable to MasTec, Inc.	[1]	40,970	(2,692)
Comprehensive income (loss)		42,441	(5,267)
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		0	0
Costs of revenue, excluding depreciation and amortization		0	0
Depreciation and amortization		0	0
General and administrative expenses		600	600
Interest expense (income), net		0	0
Equity in (earnings) losses of unconsolidated affiliates		0	0
Other expense (income), net		0	0
Income (loss) before income taxes		(600)	(600)
(Provision for) benefit from income taxes		200	200
Net (loss) income before equity in income from subsidiaries		(400)	(400)
Equity in income (losses) from subsidiaries, net of tax		41,400	(2,300)
Net income (loss)		41,000	(2,700)
Net loss attributable to non-controlling interests		0	0
Net income (loss) attributable to MasTec, Inc.		41,000	(2,700)
Comprehensive income (loss)		42,800	(5,100)
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		1,085,100	878,100
Costs of revenue, excluding depreciation and amortization		891,100	777,200
Depreciation and amortization		34,100	31,300
General and administrative expenses		59,500	50,000
Interest expense (income), net		27,800	27,400
Equity in (earnings) losses of unconsolidated affiliates		0	0
Other expense (income), net		0	(11,300)
Income (loss) before income taxes		72,600	3,400
(Provision for) benefit from income taxes		(26,600)	(1,300)
Net (loss) income before equity in income from subsidiaries		46,000	2,100
Equity in income (losses) from subsidiaries, net of tax		0	0
Net income (loss)		46,000	2,100
Net loss attributable to non-controlling interests		0	0
Net income (loss) attributable to MasTec, Inc.		46,000	2,100
Comprehensive income (loss)		46,000	2,100
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		94,200	96,100
Costs of revenue, excluding depreciation and amortization		101,100	107,200
Depreciation and amortization		8,800	7,700
General and administrative expenses		4,700	9,400
Interest expense (income), net		(15,200)	(15,200)
Equity in (earnings) losses of unconsolidated affiliates		(1,600)	(3,100)
Other expense (income), net		400	(2,100)
Income (loss) before income taxes		(4,000)	(7,800)
(Provision for) benefit from income taxes		(1,000)	3,200
Net (loss) income before equity in income from subsidiaries		(5,000)	(4,600)
Equity in income (losses) from subsidiaries, net of tax		0	0
Net income (loss)		(5,000)	(4,600)
Net loss attributable to non-controlling interests		(300)	(200)
Net income (loss) attributable to MasTec, Inc.		(4,700)	(4,400)
Comprehensive income (loss)		(3,200)	(7,000)
Eliminations [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		(21,100)	0
Costs of revenue, excluding depreciation and amortization		(21,100)	0
Depreciation and amortization		0	0
General and administrative expenses		0	0
Interest expense (income), net		0	0
Equity in (earnings) losses of unconsolidated affiliates		0	0
Other expense (income), net		0	0
Income (loss) before income taxes		0	0
(Provision for) benefit from income taxes		0	0
Net (loss) income before equity in income from subsidiaries		0	0
Equity in income (losses) from subsidiaries, net of tax		(41,400)	2,300
Net income (loss)		(41,400)	2,300
Net loss attributable to non-controlling interests		0	0
Net income (loss) attributable to MasTec, Inc.		(41,400)	2,300
Comprehensive income (loss)		$ (43,200)	$ 4,700

[1] Calculated as total net income (loss) less amounts attributable to non-controlling interests.