Acquisitions (Schedule of Business Acquisition Pro Forma Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Business Acquisitions, Pro Forma Information [Abstract]
Business acquisitions, pro forma information, description			The unaudited supplemental pro forma financial information presented below has been prepared by adjusting the historical results of MasTec to include the historical results of the acquired businesses described above. The unaudited supplemental pro forma combined historical results were then adjusted (i) to remove one-time acquisition costs; (ii) to increase amortization expense resulting from the incremental intangible assets acquired in such acquisitions; (iii) to increase interest expense as a result of the cash consideration paid; and (iv) to reduce interest expense from the repayment of acquired debt. The unaudited supplemental pro forma financial information does not include any adjustments to reflect the impact of cost savings or other synergies that may result from these acquisitions. As noted above, the unaudited supplemental pro forma financial information does not purport to be indicative of the actual results that would have been achieved by the combined companies for the periods presented or that may be achieved by the combined companies in the future.
Business acquisitions, pro forma revenue	$ 1,161.9	$ 1,135.9	$ 2,186.4	$ 2,249.9
Business acquisitions, pro forma net income from continuing operations	33.3	37.2	47.9	64.2
Business acquisitions, acquiree revenue, year over year incremental impact	89.4	85.6	209.2	128.7
Business acquisitions, acquiree net income from continuing operations, year over year incremental impact	$ 1.1	$ 3.5	$ 2.2	$ 5.3