XML 76 R58.htm IDEA: XBRL DOCUMENT v3.6.0.2
Stock-based Compensation - Summary of Restricted Stock Activity (Detail) - Restricted Stock - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Beginning Balance, Number of Shares, Outstanding 314,048 241,505  
Number of Shares, Granted 237,187    
Number of Shares, Vested (191,004)    
Number of Shares, Forfeitures (5,245)    
Ending Balance, Number of Shares, Outstanding 354,986 314,048 241,505
Beginning Balance, Weighted Average Grant Price, Outstanding $ 49.57    
Weighted Average Grant Price, Granted 5.46 $ 26.70 $ 101.20
Weighted Average Grant Price, Vested 58.80    
Weighted Average Grant Price, Forfeitures 32.07    
Ending Balance, Weighted Average Grant Price, Outstanding $ 15.60 $ 49.57