Employee Benefits - Summary of Stock Option Plans (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding beginning of period, Options | shares	1,001
Grants, Options | shares	163
Exercises, Options | shares	(186)
Forfeitures, Options | shares	0
Cancellations, Options | shares	(9)
Outstanding end of period, Options | shares	969
Exercisable end of period, Options | shares	612
Outstanding beginning of period, Weighted Average Exercise Price | $ / shares	$ 15.31
Grants, Weighted Average Exercise Price | $ / shares	19.52
Exercises, Weighted average exercise price | $ / shares	13.27
Forfeitures, Weighted average exercise price | $ / shares	0
Cancellations, Weighted average exercise price | $ / shares	20.26
Outstanding end of period, Weighted Average Exercise Price | $ / shares	16.55
Exercisable end of period, Weighted average exercise price | $ / shares	$ 16.62
Outstanding end of period, Weighted Average remaining life	6 years 2 months 8 days
Exercisable end of period, Weighted Average remaining life	4 years 11 months 19 days
Outstanding end of period, Aggregate intrinsic value | $	$ 14,515
Exercisable end of period, Aggregate intrinsic value | $	$ 9,124