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Stock Plans - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options exercisable period after grant date   3 years    
Restricted stock and restricted stock unit vest period after grant date   3 years    
Average closing share price, period   1 year    
Stock options expiration period   10 years    
Cash proceeds from exercise of options   $ 1,930 $ 6,926 $ 9,643
Excess tax benefit (provision) related to stock plans   596 2,573 2,246
Aggregate intrinsic value of stock options exercisable   14,000    
Aggregate intrinsic value of stock options outstanding   11,500    
Total intrinsic value of stock options exercised   500 3,700 4,000
Unrecognized stock-based compensation expense   $ 4,400    
Weighted average period over which unrecognized stock-based compensation expense is expected to be recognized, in years   2 years    
Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Percentage of target award based on achieving targeted performance conditions   0.00%    
Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Percentage of target award based on achieving targeted performance conditions   200.00%    
Percentage of target award based on achieving targeted return on net assets based on which final number of shares to be issued for performance stock units   133.60%    
Stock Options        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Excess tax benefit (provision) related to stock plans   $ (100) 1,000 500
Restricted Stock and Unit Activity        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Fair value of stock units vested   5,300 $ 5,800 $ 9,700
Performance Stock Unit Activity        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period (in years) 3 years      
Fair value of stock units vested   $ 2,000    
Management        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares reserved for future grants   1,178,625    
Non Employee Directors        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares reserved for future grants   154,315    
Stock Options        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options expiration period   10 years