Quarterly report pursuant to Section 13 or 15(d)

Equity-Based Compensation (Performance Units to be Settled in Common Stock) - Additional Information (Detail)

v3.7.0.1
Equity-Based Compensation (Performance Units to be Settled in Common Stock) - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Non-cash stock-based compensation $ 11,866 $ 13,719
Performance Units [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Required performance period 3 years  
Performance units vesting conditions These performance units cliff-vest at the end of a three-year performance period based on achievement of company performance goals established by Quanta's compensation committee.  
Performance units granted 300,000 200,000
Granted, weighted average grant date fair value, per share $ 36.31 $ 22.62
Non-cash stock-based compensation $ 700 $ 500
Performance units vested 100,000 0
Number of common shares issued in connection with performance units 100,000 0
Performance Units [Member] | Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Performance units performance percentage 0.00%  
Performance Units [Member] | Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Performance units performance percentage 200.00%