Supplemental Guarantor Financial Information (Condensed Consolidating Statements of Operations and Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended									6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2014	[1]	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue	$ 1,231,300		$ 1,315,488	$ 1,107,232	$ 957,818	$ 1,159,100	$ 1,269,400	$ 977,600	$ 918,600	$ 2,065,050	$ 3,380,538	$ 4,611,803	$ 4,324,787	$ 3,726,789
Costs of revenue, excluding depreciation and amortization	1,063,100		1,122,861	950,715	841,324	987,000	1,081,100	822,700	791,500	1,792,040	2,914,901	3,977,963	3,682,367	3,239,195
Depreciation and amortization			41,747	36,755	33,494					70,249	111,996	154,452	140,926	91,958
General and administrative expenses			59,889	54,237	53,327					107,564	167,454	238,305	215,402	157,524
Interest expense, net			12,643	12,949	12,003					24,952	37,595	50,769	46,442	37,376
Loss on extinguishment of debt												0	5,624	0
Other (income) expense, net			(1,416)	(1,923)	(2,083)					(4,007)	(5,424)	(8,116)	(6,188)	8,017
Income from continuing operations before income taxes			79,764	54,499	19,753					74,252	154,016	198,430	240,214	192,719
Benefit from (provision for) income taxes			(30,319)	(20,761)	(7,489)					(28,250)	(58,569)	(76,429)	(92,542)	(76,080)
Net income from continuing operations	26,600		49,445	33,738	12,264	42,900	49,900	35,500	19,300	46,002	95,447	122,001	147,672	116,639
Net loss from discontinued operations	(5,900)		(320)	(149)	(122)	(1,300)	(3,700)	(500)	(900)	(272)	(592)	(6,452)	(6,456)	(9,223)
Equity in income from subsidiaries, net of tax												0	0	0
Net income			49,125	33,589	12,142					45,730	94,855	115,549	141,216	107,416
Net (loss) income attributable to non-controlling interests	(400)		139	(136)	45	100	100	100	0	(91)	48	(374)	266	(10)
Net income attributable to MasTec, Inc.	$ 21,100		48,986	33,725	12,097	$ 41,500	$ 46,100	$ 34,900	$ 18,400	45,821	94,807	115,923	140,950	107,426
Comprehensive income (loss)			$ 36,174	$ 41,265	$ 6,806					$ 48,070	$ 84,244	94,831	133,431	109,861
Reportable Legal Entities [Member] | MasTec, Inc. [Member]
Condensed Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue												0	0	0
Costs of revenue, excluding depreciation and amortization												0	0	0
Depreciation and amortization												0	0	0
General and administrative expenses												2,500	2,100	1,700
Interest expense, net												0	0	0
Loss on extinguishment of debt													0
Other (income) expense, net												0	0	0
Income from continuing operations before income taxes												(2,500)	(2,100)	(1,700)
Benefit from (provision for) income taxes												1,000	800	700
Net income from continuing operations												(1,500)	(1,300)	(1,000)
Net loss from discontinued operations												0	0	0
Equity in income from subsidiaries, net of tax												117,400	142,200	108,400
Net income												115,900	140,900	107,400
Net (loss) income attributable to non-controlling interests												0	0	0
Net income attributable to MasTec, Inc.												115,900	140,900	107,400
Comprehensive income (loss)												95,200	133,100	109,900
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue												3,768,400	3,903,800	3,563,200
Costs of revenue, excluding depreciation and amortization												3,226,200	3,321,300	3,094,200
Depreciation and amortization												119,300	120,100	89,000
General and administrative expenses												208,500	184,600	147,400
Interest expense, net												47,800	45,500	37,300
Loss on extinguishment of debt													5,600
Other (income) expense, net												(1,900)	(6,100)	7,800
Income from continuing operations before income taxes												168,500	232,800	187,500
Benefit from (provision for) income taxes												(70,600)	(91,900)	(75,600)
Net income from continuing operations												97,900	140,900	111,900
Net loss from discontinued operations												0	0	0
Equity in income from subsidiaries, net of tax												0	0	0
Net income												97,900	140,900	111,900
Net (loss) income attributable to non-controlling interests												0	0	0
Net income attributable to MasTec, Inc.												97,900	140,900	111,900
Comprehensive income (loss)												97,900	140,900	112,500
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue												847,700	425,600	166,600
Costs of revenue, excluding depreciation and amortization												756,100	365,700	148,000
Depreciation and amortization												35,200	20,800	3,000
General and administrative expenses												27,300	28,700	8,400
Interest expense, net												3,000	900	100
Loss on extinguishment of debt													0
Other (income) expense, net												(6,300)	0	200
Income from continuing operations before income taxes												32,400	9,500	6,900
Benefit from (provision for) income taxes												(6,800)	(1,400)	(1,200)
Net income from continuing operations												25,600	8,100	5,700
Net loss from discontinued operations												(6,500)	(6,500)	(9,200)
Equity in income from subsidiaries, net of tax												0	0	0
Net income												19,100	1,600	(3,500)
Net (loss) income attributable to non-controlling interests												(400)	300	0
Net income attributable to MasTec, Inc.												19,500	1,300	(3,500)
Comprehensive income (loss)												(1,600)	(6,200)	(1,600)
Eliminations [Member]
Condensed Consolidating Statements of Operations and Comprehensive Income [Line Items]
Revenue												(4,300)	(4,600)	(3,000)
Costs of revenue, excluding depreciation and amortization												(4,300)	(4,600)	(3,000)
Depreciation and amortization												0	0	0
General and administrative expenses												0	0	0
Interest expense, net												0	0	0
Loss on extinguishment of debt													0
Other (income) expense, net												0	0	0
Income from continuing operations before income taxes												0	0	0
Benefit from (provision for) income taxes												0	0	0
Net income from continuing operations												0	0	0
Net loss from discontinued operations												0	0	0
Equity in income from subsidiaries, net of tax												(117,400)	(142,200)	(108,400)
Net income												(117,400)	(142,200)	(108,400)
Net (loss) income attributable to non-controlling interests												0	0	0
Net income attributable to MasTec, Inc.												(117,400)	(142,200)	(108,400)
Comprehensive income (loss)												$ (96,700)	$ (134,400)	$ (110,900)

[1] Preliminary, unaudited fourth quarter and full year 2014 results were previously issued pursuant to a press release dated February 26, 2015 and not previously filed in a report under the Securities Exchange Act of 1934, as amended. The unaudited quarterly information for the three month period ended December 31, 2014 in the table above includes the effect of adjustments determined by management following the review process described in Note 2 - Independent Investigation of the Audit Committee and Related Restatements.