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Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of shares authorized under plan       3,450,000
Stock Option [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock award grants vest period first 3 years      
Stock award grants vest period second 4 years      
Stock award grants vest period third 5 years      
Weighted-average grant date fair value of stock options granted $ 20.26 $ 17.28 $ 20.91  
Intrinsic value of stock options exercised $ 31,153 $ 2,307 $ 3,448  
Allocated Share-based compensation expense 3,701 $ 3,024 $ 4,354  
Unrecognized compensation expenses $ 4,079      
Recognized weighted average period 1 year 2 months 23 days      
Stock Option [Member] | Minimum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock option awards grant term 7 years      
Stock Option [Member] | Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock option awards grant term 10 years      
Restricted Common Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock award grants vest period first 1 year      
Stock award grants vest period second 3 years      
Stock award grants vest period third 4 years      
Weighted-average grant date fair value of stock options granted $ 70.09 $ 56.85 $ 66.34  
Allocated Share-based compensation expense $ 7,846 $ 6,032 $ 7,311  
Recognized weighted average period 1 year 8 months 26 days      
Total fair value of restricted common shares and units vested $ 5,923 $ 4,146 $ 4,740  
Unrecognized compensation expenses $ 10,999      
Restricted Stock And Units [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number 371,559 378,746    
Granted (in shares) 153,818      
Performance Shares [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number 247,967 172,400    
Weighted-average grant date fair value of stock options granted $ 68.71 $ 56.74 $ 66.33  
Allocated Share-based compensation expense $ 12,120 $ 4,899 $ 922  
Recognized weighted average period 1 year 2 months 23 days      
Total fair value of restricted common shares and units vested $ 0      
Unrecognized compensation expenses $ 11,173      
Granted (in shares) 86,150      
TSR-based Performance Shares [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total fair value of restricted common shares and units vested $ 365      
Unrecognized compensation expenses $ 2,251 $ 0