XML 99 R83.htm IDEA: XBRL DOCUMENT v3.6.0.2
Stock-based Compensation - Summary of Stock Award Activity (Detail) - Stock Awards [Member] - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Shares, Beginning Balance 208,503    
Granted, Shares 142,242    
Vested, Shares (32,319)    
Forfeited, Shares (61,660)    
Shares, Ending Balance 256,766 208,503  
Unvested Weighted Average Grant Date Fair Value, Beginning Balance $ 46.55    
Granted, Weighted Average Grant Date Fair Value 41.81 $ 39.11 $ 59.52
Vested, Weighted Average Grant Date Fair Value 59.41    
Forfeited, Weighted Average Grant Date Fair Value 53.05    
Unvested Weighted Average Grant Date Fair Value, Ending Balance $ 40.74 $ 46.55