XML 90 R76.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock-Based Compensation - Summary of Stock Awards (Detail) - $ / shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Non-Vested Shares (1)    
Non-Vested Shares, Beginning Balance (in shares) 805,757  
Non-Vested Shares, Awarded (in shares) 519,724  
Non-Vested Shares, Vested (in shares) (219,443)  
Non-Vested Shares, Cancelled (in shares) (246,106)  
Non-Vested Shares, Ending Balance (in shares) 859,932  
Weighted Average Grant Date Fair Value    
Weighted Average Grant Date Fair Value, Beginning Balance (in dollars per share) $ 30.98  
Weighted Average Grant Date Fair Value, Awarded (in dollars per share) 38.52  
Weighted Average Grant Date Fair Value, Vested (in dollars per share) 32.97  
Weighted Average Grant Date Fair Value, Cancelled (in dollars per share) 33.09  
Weighted Average Grant Date Fair Value, Ending Balance (in dollars per share) $ 34.43  
Performance Shares    
Weighted Average Grant Date Fair Value    
Maximum shares that could vest (percent) 200.00%  
Maximum number that could vest (in shares) 1,218,359 1,038,272