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Stock Repurchase Program - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Sep. 05, 2018
Mar. 20, 2018
Apr. 30, 2019
Apr. 30, 2018
Apr. 30, 2019
Equity Class Of Treasury Stock [Line Items]          
Stock repurchase program, total cost     $ 5,300,000 $ 4,800,000  
Common Stock [Member]          
Equity Class Of Treasury Stock [Line Items]          
Stock repurchase program, authorized amount to repurchase issued and outstanding common stock $ 50,000,000        
Stock repurchase program, expiration date Sep. 04, 2020 Mar. 19, 2020      
Stock repurchase program, remaining authorized, amount     $ 41,300,000   $ 41,300,000
Stock repurchase program, number of remaining shares purchased     495,475 238,547 495,475
Stock repurchase program, total cost     $ 5,300,000   $ 5,300,000
Stock repurchase program, average price per share     $ 10.77   $ 10.77
Common Stock [Member] | Maximum [Member]          
Equity Class Of Treasury Stock [Line Items]          
Stock repurchase program, authorized amount to repurchase issued and outstanding common stock   $ 50,000,000