Leases - Operating Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Lease, Cost [Abstract]
Operating lease costs	$ 2,358	$ 6,755
Amortization of assets	311	933
Interest on lease liabilities	29	84
Total finance lease costs	340	1,017
Variable lease cost	448	1,314
Short-term lease costs	181	477
Total lease costs	$ 3,327	$ 9,563