Employee Benefits - Summary of Nonvested Options (Detail) - $ / shares shares in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Nonvested beginning of period, Options	389
Granted, Options	77
Vested, Options	(205)
Forfeitures, Options	(52)
Nonvested end of period, Options	209	389
Nonvested beginning of period, Weighted Average Grant Date Fair Value	$ 3.24
Granted, Weighted Average Grant Date Fair Value	3.61	$ 3.27	$ 2.65
Vested, Weighted Average Grant Date Fair Value	3.39
Forfeitures, Weighted Average Grant Date Fair Value	3.25
Nonvested end of period, Weighted Average Grant Date Fair Value	$ 3.24