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Stock Repurchase Program - Additional Information (Detail) - USD ($)
 1 Months Ended 9 Months Ended 17 Months Ended
Dec. 10, 2015
Oct. 31, 2015
Oct. 31, 2015
May. 22, 2014
Equity, Class of Treasury Stock [Line Items]        
Stock repurchase program, Expiration date   May 31, 2016    
Repurchase and retirement of common stock, shares     523,000  
Repurchase and retirement of common stock   $ 5,881,000 $ 10,700,000  
Stock repurchase program, remaining authorized repurchase amount   $ 19,300,000 $ 19,300,000  
Subsequent Event [Member]        
Equity, Class of Treasury Stock [Line Items]        
Repurchase and retirement of common stock, shares 142,000      
Repurchase and retirement of common stock $ 2,400,000      
Maximum [Member]        
Equity, Class of Treasury Stock [Line Items]        
Stock repurchase program, Authorized amount       $ 30,000,000