Employee Benefits - Summary of Nonvested Options (Detail) - $ / shares shares in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Nonvested beginning of period, Options	403
Granted, Options	163
Vested, Options	(209)
Forfeitures, Options	0
Nonvested end of period, Options	357	403
Nonvested beginning of period, Weighted Average Grant Date Fair Value	$ 5.7
Granted, Weighted Average Grant Date Fair Value	9.26	$ 9.18	$ 3.54
Vested, Weighted Average Grant Date Fair Value	5.73
Forfeitures, Weighted Average Grant Date Fair Value	0
Nonvested end of period, Weighted Average Grant Date Fair Value	$ 7.3