Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		$ 1,586,181	$ 1,111,010	$ 3,792,811	$ 3,180,906
Costs of revenue, excluding depreciation and amortization		1,368,988	972,711	3,321,571	2,805,072
Depreciation and amortization		42,584	42,196	122,249	128,048
General and administrative expenses		67,131	63,798	195,031	207,077
Interest expense (income), net		13,097	11,964	37,895	35,845
Equity in losses (earnings) of unconsolidated affiliates		6	371	(3,549)	3,594
Other (income) expense, net		(971)	6,331	(12,803)	748
Income before income taxes		95,346	13,639	132,417	522
(Provision for) benefit from income taxes		(38,816)	(6,197)	(54,331)	(3,288)
Net income (loss) before equity in income (losses) from subsidiaries		56,500	7,400	78,100	(2,800)
Equity in income (losses) from subsidiaries, net of tax		0	0	0	0
Net income (loss)		56,530	7,442	78,086	(2,766)
Net income (loss) attributable to non-controlling interests		253	(176)	414	(420)
Net income (loss) attributable to MasTec, Inc.	[1]	56,277	7,618	77,672	(2,346)
Comprehensive income (loss)		54,731	(5,888)	69,571	(34,816)
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		0	0	0	0
Costs of revenue, excluding depreciation and amortization		0	0	0	0
Depreciation and amortization		0	0	0	0
General and administrative expenses		600	700	1,700	1,900
Interest expense (income), net		0	0	0	0
Equity in losses (earnings) of unconsolidated affiliates		0	0	0	0
Other (income) expense, net		0	0	0	0
Income before income taxes		(600)	(700)	(1,700)	(1,900)
(Provision for) benefit from income taxes		200	300	600	800
Net income (loss) before equity in income (losses) from subsidiaries		(400)	(400)	(1,100)	(1,100)
Equity in income (losses) from subsidiaries, net of tax		56,700	8,000	78,800	(1,300)
Net income (loss)		56,300	7,600	77,700	(2,400)
Net income (loss) attributable to non-controlling interests		0	0	0	0
Net income (loss) attributable to MasTec, Inc.		56,300	7,600	77,700	(2,400)
Comprehensive income (loss)		54,500	(5,700)	69,200	(34,400)
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		1,493,900	963,700	3,521,500	2,657,900
Costs of revenue, excluding depreciation and amortization		1,282,300	841,900	3,054,500	2,309,400
Depreciation and amortization		33,700	33,200	96,600	98,100
General and administrative expenses		60,600	57,000	172,100	184,900
Interest expense (income), net		28,600	27,700	83,800	82,900
Equity in losses (earnings) of unconsolidated affiliates		0	0	0	0
Other (income) expense, net		(3,400)	6,000	(12,700)	300
Income before income taxes		92,100	(2,100)	127,200	(17,800)
(Provision for) benefit from income taxes		(33,400)	1,300	(47,300)	7,900
Net income (loss) before equity in income (losses) from subsidiaries		58,700	(800)	79,900	(9,900)
Equity in income (losses) from subsidiaries, net of tax		0	0	0	0
Net income (loss)		58,700	(800)	79,900	(9,900)
Net income (loss) attributable to non-controlling interests		0	0	0	0
Net income (loss) attributable to MasTec, Inc.		58,700	(800)	79,900	(9,900)
Comprehensive income (loss)		58,700	(800)	79,900	(9,900)
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		112,700	149,900	302,200	530,200
Costs of revenue, excluding depreciation and amortization		107,200	133,400	298,000	502,900
Depreciation and amortization		8,900	9,000	25,600	29,900
General and administrative expenses		5,900	6,100	21,200	20,300
Interest expense (income), net		(15,500)	(15,700)	(45,900)	(47,100)
Equity in losses (earnings) of unconsolidated affiliates		0	400	(3,500)	3,600
Other (income) expense, net		2,300	300	(100)	400
Income before income taxes		3,900	16,400	6,900	20,200
(Provision for) benefit from income taxes		(5,600)	(7,800)	(7,600)	(12,000)
Net income (loss) before equity in income (losses) from subsidiaries		(1,700)	8,600	(700)	8,200
Equity in income (losses) from subsidiaries, net of tax		0	0	0	0
Net income (loss)		(1,700)	8,600	(700)	8,200
Net income (loss) attributable to non-controlling interests		300	(200)	400	(500)
Net income (loss) attributable to MasTec, Inc.		(2,000)	8,800	(1,100)	8,700
Comprehensive income (loss)		(3,600)	(4,800)	(9,200)	(23,700)
Eliminations [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income (Loss) [Line Items]
Revenue		(20,400)	(2,600)	(30,900)	(7,200)
Costs of revenue, excluding depreciation and amortization		(20,400)	(2,600)	(30,900)	(7,200)
Depreciation and amortization		0	0	0	0
General and administrative expenses		0	0	0	0
Interest expense (income), net		0	0	0	0
Equity in losses (earnings) of unconsolidated affiliates		0	0	0	0
Other (income) expense, net		0	0	0	0
Income before income taxes		0	0	0	0
(Provision for) benefit from income taxes		0	0	0	0
Net income (loss) before equity in income (losses) from subsidiaries		0	0	0	0
Equity in income (losses) from subsidiaries, net of tax		(56,700)	(8,000)	(78,800)	1,300
Net income (loss)		(56,700)	(8,000)	(78,800)	1,300
Net income (loss) attributable to non-controlling interests		0	0	0	0
Net income (loss) attributable to MasTec, Inc.		(56,700)	(8,000)	(78,800)	1,300
Comprehensive income (loss)		$ (54,900)	$ 5,400	$ (70,300)	$ 33,300

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