Operating Leases - Lease Expense and Cash Payments & Weighted-Average Remaining Lease Term and Discount Rate (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Leases [Abstract]
Operating lease expense	$ 979	$ 1,085	$ 1,978	$ 2,173
Cash payments on lease liabilities	$ 1,090	$ 1,167	$ 2,176	$ 2,519
Weighted-average remaining lease term	4 years 7 months 6 days	5 years	4 years 7 months 6 days	5 years
Weighted-average discount rate	4.42%	4.76%	4.42%	4.76%