Employee Benefits - Summary of Nonvested Options (Detail) - $ / shares shares in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Nonvested beginning of period, Options	281
Granted, Options	479
Vested, Options	(188)
Forfeitures, Options	(83)
Cancelled, Options	(100)
Nonvested end of period, Options	389	281
Nonvested beginning of period, Weighted Average Grant Date Fair Value	$ 3.00
Granted, Weighted Average Grant Date Fair Value	3.27	$ 2.65	$ 3.46
Vested, Weighted Average Grant Date Fair Value	3.09
Forfeitures, Weighted Average Grant Date Fair Value	2.99
Cancelled, Weighted Average Grant Date Fair Value	3.22
Nonvested end of period, Weighted Average Grant Date Fair Value	$ 3.24