Earnings Per Share (Narrative) (Details) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Computation of earnings per share, methodology	Basic earnings or loss per share is computed by dividing net income or loss available to MasTec’s common shareholders by the weighted average number of common shares outstanding for the period. For purposes of calculating basic and diluted earnings per share, vested restricted stock awards are considered outstanding. Diluted earnings per share is computed by dividing net income available to MasTec’s common shareholders by the weighted average number of fully diluted shares, as calculated under the treasury stock method, which includes the effect of dilutive common stock equivalents, including from the exercise of outstanding stock options or the vesting of unvested restricted shares. If the Company reports a loss, rather than income, the computation of diluted loss per share excludes dilutive common stock equivalents, as their effect would be anti-dilutive. For the three month periods ended March 31, 2016 and 2015, the Company reported a net loss, which resulted in the exclusion of 610,657 and 502,217 weighted average dilutive common stock equivalents, respectively, from the calculation of diluted net loss per share.
Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average anti-dilutive common stock equivalents (in shares)	615,143	807,567
Common Stock Equivalents Excluded Due To Net Loss [Member] | Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average anti-dilutive common stock equivalents (in shares)	610,657	502,217