Leases - Operating Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease, Cost [Abstract]
Operating lease costs	$ 2,608	$ 2,122
Amortization of assets	312	311
Interest on lease liabilities	15	29
Total finance lease costs	327	340
Variable lease cost	525	406
Short-term lease costs	110	164
Total lease costs	$ 3,570	$ 3,032