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Stock-Based Compensation Plans - Additional Information (Detail) - USD ($)
12 Months Ended
May 31, 2008
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock option plan, options outstanding   414,000 428,000  
Stock options granted under Black-Scholes options pricing model   65,000    
Cash received from stock option exercises   $ 1,277,000 $ 231,000 $ 2,215,000
Common stock, shares outstanding   135,526,025 135,600,501  
Number of common shares, options exercisable   212,000    
2008 Equity Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Authorized issuance of shares of Company common stock 9,000,000      
Expiry of equity incentive plan   2018    
Common stock available for future issuance   6,607,285    
2008 Stock Option Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock option plan, options outstanding   152,700    
Stock Options [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total expenses on stock option   $ 220,000 $ 183,000 $ 352,000
Stock options granted under Black-Scholes options pricing model   64,500 217,500 1,500
Vesting period   5 years    
Intrinsic value of options exercised   $ 262,000 $ 144,000 $ 1,300,000
Unrecognized compensation cost related to nonvested options granted   $ 480,000    
Weighted-average period for expected cost recognized   2 years 9 months 18 days    
Fair value of options vested   $ 258,000 183,000 520,000
Cash received from stock option exercises   $ 1,300,000 $ 232,000 $ 2,200,000
Common stock, shares outstanding   414,300    
Options exercisable lower price range   $ 11.03    
Options exercisable upper price range   $ 24.83    
Stock Options [Member] | Common Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of common shares, options exercisable   212,100    
Restricted Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost related to nonvested options granted   $ 9,400,000    
2008 Equity Incentive Plan, granted restricted stock awards   395,000    
Weighted average fair value of restricted stock   $ 20.43 $ 18.20 $ 20.76
Amount of compensation cost recognized   $ 5,000,000.0 $ 5,300,000 $ 5,200,000
Restricted Stock [Member] | 2008 Equity Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
2008 Equity Incentive Plan, granted restricted stock awards   394,884 358,464 217,000
Restricted Stock [Member] | 2008 Equity Incentive Plan [Member] | Minimum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period   1 year    
Restricted Stock [Member] | 2008 Equity Incentive Plan [Member] | Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period   5 years