Quarterly Information (Unaudited) (Schedule of Quarterly Financial Information (Unaudited)) (Details) - USD ($) $ / shares in Units, $ 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
Selected Quarterly Financial Information [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
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 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:
Basic (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
Diluted (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