Stock-based Compensation Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Stock-Based Compensation Activity [Line Items]
Unrecognized compensation costs, nonvested awards, amount	$ 12.5
Unrecognized compensation costs, nonvested awards, weighted average recognition period	2 years 3 months 18 days
Restricted Stock Awards [Member]
Stock-Based Compensation Activity [Line Items]
Units granted	102,000	90,000
Weighted average grant date fair value	$ 35.84	$ 43.02
Restricted Stock Unit Awards [Member]
Stock-Based Compensation Activity [Line Items]
Units granted	16,000	14,000
Weighted average grant date fair value	$ 31.72	$ 42.79
Employee Stock Purchase Plan [Member]
Stock-Based Compensation Activity [Line Items]
Shares issued	23,000	10,000