Acquisitions and Other Investments (Schedule of Business Acquisition Pro Forma Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Acquisitions During 2013 [Member]
Business Acquisition [Line Items]
Pro forma information, description			The unaudited pro forma combined results of operations presented below for three and six month periods ended June 30, 2013 and 2012, respectively, have been prepared by adjusting the historical results of MasTec to include the historical results of the acquisitions described above as if they occurred on January 1, 2012. These unaudited pro forma combined historical results were then adjusted for an increase in amortization expense due to the incremental intangible assets recorded related to the acquisitions, a reduction in interest income resulting from the cash consideration paid and a reduction in interest expense relating to the repayment of acquired debt. The unaudited pro forma results of operations do not include any adjustments to eliminate the impact of acquisition related costs or any cost savings or other synergies that may result from these acquisitions. As noted above, the unaudited pro forma results of operations do not purport to be indicative of the actual results that would have been achieved by the combined company for the periods presented or that may be achieved by the combined company in the future.
Pro forma revenue	$ 995.1	$ 1,039.5	$ 1,987.9	$ 1,849.8
Pro forma net income	34.7	29.6	57.9	47.2
Aquiree revenue since acquisition date	39.6		39.6
Acquiree net income since acquisition date	1.5		1.5
Acquisitions During 2012 [Member]
Business Acquisition [Line Items]
Aquiree revenue since acquisition date	47.0		90.0
Acquiree net income since acquisition date	$ 2.0		$ 3.8