Supplemental Guarantor Financial Information (Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue	$ 1,066,629	$ 1,107,232	$ 2,069,896	$ 2,065,050
Costs of revenue, excluding depreciation and amortization	945,947	950,715	1,832,361	1,792,040
Depreciation and amortization	43,254	36,755	85,852	70,249
General and administrative expenses	69,250	54,237	143,279	107,564
Interest expense (income), net	12,907	12,949	23,880	24,952
Other (income) expense, net	(2,353)	(1,923)	(2,360)	(4,007)
(Loss) income from continuing operations before income taxes	(2,376)	54,499	(13,116)	74,252
(Provision for) benefit from income taxes	(1,444)	(20,761)	2,908	(28,250)
Net (loss) income from continuing operations	(3,820)	33,738	(10,208)	46,002
Net loss from discontinued operations	0	(149)	0	(272)
Equity in (loss) income from subsidiaries, net of tax	0	0	0	0
Net (loss) income	(3,820)	33,589	(10,208)	45,730
Net loss attributable to non-controlling interests	(120)	(136)	(245)	(91)
Net (loss) income attributable to MasTec, Inc.	(3,700)	33,725	(9,963)	45,821
Comprehensive (loss) income	(511)	41,265	(28,927)	48,070
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue	0	0	0	0
Costs of revenue, excluding depreciation and amortization	0	0	0	$ 0
Depreciation and amortization	0	0	0
General and administrative expenses	600	700	1,300	$ 1,200
Interest expense (income), net	0	0	0	0
Other (income) expense, net	0	0	0	0
(Loss) income from continuing operations before income taxes	(600)	(700)	(1,300)	(1,200)
(Provision for) benefit from income taxes	300	200	500	500
Net (loss) income from continuing operations	(300)	(500)	(800)	(700)
Net loss from discontinued operations		0		0
Equity in (loss) income from subsidiaries, net of tax	(3,300)	34,200	(9,100)	46,500
Net (loss) income	(3,600)	33,700	(9,900)	45,800
Net loss attributable to non-controlling interests	0	0	0	0
Net (loss) income attributable to MasTec, Inc.	(3,600)	33,700	(9,900)	45,800
Comprehensive (loss) income	(400)	41,400	(28,700)	48,200
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue	891,200	960,900	1,694,100	1,751,900
Costs of revenue, excluding depreciation and amortization	784,700	816,400	1,467,400	1,509,600
Depreciation and amortization	32,700	29,400	65,000	57,400
General and administrative expenses	61,700	48,000	127,900	95,900
Interest expense (income), net	28,100	12,300	55,300	24,100
Other (income) expense, net	(4,800)	(1,900)	(5,700)	(4,100)
(Loss) income from continuing operations before income taxes	(11,200)	56,700	(15,800)	69,000
(Provision for) benefit from income taxes	4,700	(20,900)	6,500	(27,800)
Net (loss) income from continuing operations	(6,500)	35,800	(9,300)	41,200
Net loss from discontinued operations		0		0
Equity in (loss) income from subsidiaries, net of tax	0	0	0	0
Net (loss) income	(6,500)	35,800	(9,300)	41,200
Net loss attributable to non-controlling interests	0	0	0	0
Net (loss) income attributable to MasTec, Inc.	(6,500)	35,800	(9,300)	41,200
Comprehensive (loss) income	(6,500)	35,800	(9,300)	41,200
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue	178,500	146,400	380,300	313,300
Costs of revenue, excluding depreciation and amortization	164,300	134,400	369,500	282,500
Depreciation and amortization	10,600	7,400	20,900	12,800
General and administrative expenses	7,000	5,500	14,100	10,500
Interest expense (income), net	(15,200)	600	(31,400)	900
Other (income) expense, net	2,400	0	3,300	100
(Loss) income from continuing operations before income taxes	9,400	(1,500)	3,900	6,500
(Provision for) benefit from income taxes	(6,400)	(100)	(4,100)	(1,000)
Net (loss) income from continuing operations	3,000	(1,600)	(200)	5,500
Net loss from discontinued operations		(100)		(300)
Equity in (loss) income from subsidiaries, net of tax	0	0	0	0
Net (loss) income	3,000	(1,700)	(200)	5,200
Net loss attributable to non-controlling interests	(100)	(100)	(200)	(100)
Net (loss) income attributable to MasTec, Inc.	3,100	(1,600)	0	5,300
Comprehensive (loss) income	6,400	5,900	(18,900)	7,600
Eliminations [Member]
Condensed Unaudited Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue	(3,100)	(100)	(4,500)	(100)
Costs of revenue, excluding depreciation and amortization	(3,100)	(100)	(4,500)	(100)
Depreciation and amortization	0	0	0	0
General and administrative expenses	0	0	0	0
Interest expense (income), net	0	0	0	0
Other (income) expense, net	0	0	0	0
(Loss) income from continuing operations before income taxes	0	0	0	0
(Provision for) benefit from income taxes	0	0	0	0
Net (loss) income from continuing operations	0	0	0	0
Net loss from discontinued operations		0		0
Equity in (loss) income from subsidiaries, net of tax	3,300	(34,200)	9,100	(46,500)
Net (loss) income	3,300	(34,200)	9,100	(46,500)
Net loss attributable to non-controlling interests	0	0	0	0
Net (loss) income attributable to MasTec, Inc.	3,300	(34,200)	9,100	(46,500)
Comprehensive (loss) income	$ 0	$ (41,800)	$ 28,000	$ (48,900)