Segments and Operations by Geographic Area (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Number of reportable segments			5
Segment reporting, factors used to identify entity's reportable segments			MasTec presents its continuing operations under five reportable segments: (1) Communications; (2) Oil and Gas; (3) Electrical Transmission; (4) Power Generation and Industrial and (5) Other. This structure is generally focused on broad end-user markets for MasTec's labor-based construction services and has been determined in accordance with the criteria in Accounting Standards Codification ("ASC") 280, Segment Reporting.
Segment reporting information, description of products and services			All five reportable segments derive their revenues from the engineering, installation and maintenance of infrastructure, primarily in North America.
Continuing Operations [Member] | Communications [Member] | Customer Concentration Risk [Member] | Sales Revenue, Services, Net [Member] | Utilities [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue, major customer, percentage	6.90%	11.60%	7.20%	11.20%