Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenue	$ 1,709,300	$ 2,016,600	$ 1,939,000	$ 1,518,300	$ 1,917,600	$ 1,977,200	$ 1,617,800	$ 1,396,800	$ 7,183,188	$ 6,909,417	$ 6,606,978
Costs of revenue, excluding depreciation and amortization	1,434,200	1,690,600	1,633,400	1,312,000	1,654,000	1,681,400	1,366,600	1,237,300	6,070,244	5,939,308	5,745,307
Depreciation and amortization									235,482	212,930	188,049
Goodwill and intangible asset impairment									3,319	47,662	0
General and administrative expenses									299,500	287,278	275,103
Interest expense, net									77,026	82,571	61,011
Equity in earnings of unconsolidated affiliates									(27,367)	(23,855)	(21,328)
Other expense (income), net									14,045	(1,780)	(12,990)
Income before income taxes									510,939	365,303	371,826
Provision for income taxes									(116,843)	(106,072)	(22,942)
Net income	100,700	130,100	120,200	43,100	31,800	120,500	80,400	26,500	394,096	259,231	348,884
Net income (loss) attributable to non-controlling interests									1,762	(428)	1,671
Net income attributable to MasTec, Inc.	$ 100,900	$ 128,600	$ 119,700	$ 43,100	$ 31,900	$ 120,700	$ 80,500	$ 26,600	$ 392,334	$ 259,659	$ 347,213
Earnings per share (Note 2):
Basic earnings per share (in dollars per share)	$ 1.34	$ 1.71	$ 1.59	$ 0.57	$ 0.42	$ 1.55	$ 1.02	$ 0.33	$ 5.22	$ 3.30	$ 4.29
Basic weighted average common shares outstanding									75,185	78,695	80,903
Diluted earnings per share (in dollars per share)	$ 1.33	$ 1.69	$ 1.58	$ 0.57	$ 0.41	$ 1.52	$ 1.01	$ 0.32	$ 5.17	$ 3.26	$ 4.22
Diluted weighted average common shares outstanding									75,846	79,772	82,325