Leases - Other Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash paid for leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 2,707	$ 2,893
Right Of Use Asset Obtained In Exchange for Lease Liability [Abstract]
Right-of-use assets obtained in exchange for new operating lease liabilities	3,785	1,073
Leasehold Improvements, Gross	$ 1,000	$ 0
Weighted average remaining lease term [Abstract]
Weighted average remaining lease term- operating leases	8 years 10 months 24 days
Weighted Average Discount Rate Leases [Abstract]
Weighted average discount rate - operating leases	3.50%