Other Retirement Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Nov. 30, 2014	Nov. 30, 2011
Multi-Employer Plans [Line Items]
Multi-employer plans, general nature	Certain of MasTec’s subsidiaries, including certain subsidiaries in Canada, are party to various collective bargaining agreements with unions representing certain of their employees. These agreements require the subsidiaries party to the agreements to pay specified wages, provide certain benefits to their union employees and contribute certain amounts to multiemployer pension and other multiemployer benefit plans and trusts. These contributions are recorded as a component of employee wages and salaries within costs of revenue, excluding depreciation and amortization. Contributions are generally based on fixed amounts per hour per employee for employees covered under these plans. Multiemployer plan contribution rates are determined annually and assessed on a “pay-as-you-go” basis based on union employee payrolls. Union payrolls cannot be determined for future periods because the number of union employees employed at any given time, and the plans in which they may participate, vary depending upon the location and number of ongoing projects at a given time and the need for union resources in connection with those projects. 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.
Pension [Member]
Multi-Employer Plans [Line Items]
Multi-employer plans, underfunded status, description	A multiemployer plan that is so underfunded as to be in “endangered,” “seriously endangered,” “critical,” or “critical and declining” status (as determined under the PPA) is required to adopt a funding improvement plan (“FIP”) or a rehabilitation plan (“RP”), which, among other actions, could include decreased benefits and increased employer contributions, which could take the form of a surcharge on benefit 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. Certain plans in which the Company participates are in “endangered,” “seriously endangered,”, “critical”, or “critical and declining” status. The amount of additional funds, if any, that the Company may be obligated to contribute to these plans in the future cannot be estimated due to the uncertainty of the future levels of work that could be required of the union employees covered by these plans, as well as the required future contribution rates and possible surcharges applicable to these plans.
Pension [Member] | Plans from Which the Company Terminated Participation in 2014 [Member]
Multi-Employer Plans [Line Items]
Multi-employer plans, withdrawal liability (in dollars)			$ 0
Pension [Member] | Central States Southeast and Southwest Areas Pension Fund [Member]
Multi-Employer Plans [Line Items]
Multi-employer plans, withdrawal liability (in dollars)	$ 3,000,000	$ 4,200,000		$ 6,400,000