Operating Leases - Lease Expense and Cash Payments & Weighted-Average Remaining Lease Term and Discount Rate (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Leases [Abstract]
Operating lease expense	$ 986	$ 1,075	$ 2,964	$ 3,248
Cash payments on lease liabilities	$ 1,083	$ 1,161	$ 3,259	$ 3,679
Weighted-average remaining lease term	4 years 4 months 24 days	4 years 10 months 24 days	4 years 4 months 24 days	4 years 10 months 24 days
Weighted-average discount rate	4.45%	4.62%	4.45%	4.62%