Commitments and Contingencies - Collective Bargaining Agreements and Multi-Employer Plans (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Nov. 15, 2011
Loss Contingencies [Line Items]
Multi-employer plans, collective bargaining arrangement, description	Certain of MasTec’s subsidiaries are party to various collective bargaining agreements with unions representing certain of their employees. The agreements require the subsidiaries party to the agreements to pay specified wages, provide certain benefits to their union employees and contribute certain amounts to multi-employer pension plans and employee benefit trusts. The multi-employer plan contribution rates are determined annually and assessed on a “pay-as-you-go” basis based on union employee payrolls. The collective bargaining agreements expire at various times and have typically been renegotiated and renewed on terms similar to the ones contained in the expiring agreements.
Multi-Employer Plans, Pension [Member]
Loss Contingencies [Line Items]
Multi-employer plans, underfunded status, description	A multi-employer plan that is so underfunded as to be in “endangered” or “critical” status is required to adopt a funding improvement plan (“FIP”) or a rehabilitation plan (“RP”), which, among other actions, could include decreased benefits and increased contributions. These actions are intended to improve their funding status over a period of years. If a pension fund is in critical status, a participating employer must pay an automatic surcharge in addition to contributions otherwise required under the collective bargaining agreement (“CBA”).  With some exceptions, the surcharge is equal to 5% of required contributions for the initial critical year, and 10% for each succeeding plan year in which the plan remains in critical status. The surcharge ceases on the effective date of a CBA (or other agreement) that includes contribution and benefit terms consistent with the rehabilitation plan.
Multi-Employer Plans, Pension [Member] | Withdrawal from Multiemployer Defined Benefit Plan [Member] | Central States Southeast And Southwest Areas Pension Fund [Member]
Loss Contingencies [Line Items]
Loss contingency, evaluation of estimated loss	On November 15, 2011, the Company, along with other members of the PLCA, voluntarily withdrew from Central States, a defined benefit multi-employer pension plan that is in critical status. In connection with this withdrawal, a $6.4 million withdrawal liability was established based on an estimate provided by the Central States administrator of such liability as of the date of withdrawal. The Company began paying installments towards this withdrawal liability in 2013, of which $5.4 million was outstanding as of December 31, 2013. The Company withdrew from Central States in order to mitigate its liability in connection with the plan; however, Central States has asserted that the PLCA members did not effectively withdraw in 2011 and are responsible for a withdrawal liability that includes 2011 contribution amounts. By letter dated March 14, 2013, Central States demanded $11 million in withdrawal liability from the Company, which included 2011 contribution amounts. The Company is vigorously opposing this demand because it believes that it legally and effectively withdrew from Central States on November 15, 2011. If Central States were to prevail in its assertion that the Company withdrew after that date, then the initial amount of the Company’s withdrawal liability would increase to approximately $11 million.
Multi-employer plans, withdrawal liability	$ 5.4	$ 6.4
Maximum loss	$ 11.0