Stock Repurchase Program - Additional Information (Detail) - USD ($)			3 Months Ended			9 Months Ended	12 Months Ended
	Sep. 05, 2018	Mar. 20, 2018	Jul. 31, 2020	Jul. 31, 2019	Apr. 30, 2019	Jul. 31, 2020	Oct. 31, 2019
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program, total cost				$ 3,000,000.0	$ 5,300,000
Common Stock [Member]
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program, authorized amount to repurchase issued and outstanding common stock	$ 50,000,000.0
Stock repurchase program, expiration date	Sep. 04, 2020	Mar. 19, 2020
Stock repurchase program, number of remaining shares purchased			0	222,122	495,475	0	717,597
Stock repurchase program, total cost							$ 8,300,000
Stock repurchase program, average price per share							$ 11.62
Stock repurchase program, remaining authorized, amount			$ 38,300,000			$ 38,300,000
Common Stock [Member] | Maximum [Member]
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program, authorized amount to repurchase issued and outstanding common stock		$ 50,000,000.0