Acquisitions - 2012 Acquisitions (Narrative) (Details) (USD $)	12 Months Ended			0 Months Ended	12 Months Ended		0 Months Ended		12 Months Ended
	Dec. 31, 2013 Earn-out Arrangements [Member]	Dec. 31, 2012 Earn-out Arrangements [Member]	Dec. 31, 2011 Earn-out Arrangements [Member]	Dec. 01, 2012 Bottom Line Services [Member]	Dec. 31, 2013 Bottom Line Services [Member]	Dec. 02, 2012 Bottom Line Services [Member]	Dec. 01, 2012 Bottom Line Services [Member] Earn-out Arrangements [Member]	Dec. 02, 2012 Bottom Line Services [Member] Earn-out Arrangements [Member]	Dec. 31, 2013 Other 2012 Acquisitions [Member]
Business Acquisition [Line Items]
Effective date of acquisition					Dec. 01, 2012
Business combination, percentage of voting interests acquired						100.00%
Business acquisition, name of acquired entity					Bottom Line Services, LLC
Business acquisition, description of acquired entity					BLS, which is included in the Company's Oil and Gas segment, provides pipeline and facilities construction, painting and maintenance services, primarily in eastern Texas.				MasTec acquired a former subcontractor to MasTec's oil and gas business, which provides self-perform clearing and trenching services for natural gas and petroleum pipeline infrastructure construction and is included in the Company's Oil and Gas segment. MasTec also acquired a former subcontractor to MasTec's wireless business, which provides self-perform communications tower construction, installation, maintenance and other services in support of telecommunications infrastructure construction and is included in the Company's Communications segment.
Acquisition payments in cash				$ 67,600,000
Earn-out period								5 years
Estimated fair value of contingent consideration	$ 29,971,000	$ 66,700,000	$ 48,111,000				$ 11,100,000