Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Lease, Cost [Abstract]
Operating lease cost	$ 856	$ 829	$ 2,615	$ 2,458
Variable lease cost	286	260	805	497
Short-term Lease, Cost	32	73	98	127
Total lease cost	$ 1,174	$ 1,162	$ 3,518	$ 3,081