Leases - Other Information Related to Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 3,306	$ 3,586
New lease liabilities, net of new right-of-use-assets	0	229
Lease liabilities arising from obtaining right-of-use-assets	$ 0	$ 7,822