Leases - Operating Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2020	Mar. 31, 2020
Lease, Cost [Abstract]
Operating lease costs	$ 2,275	$ 4,397
Amortization of assets	311	622
Interest on lease liabilities	26	55
Total finance lease costs	337	677
Variable lease cost	460	866
Short-term lease costs	132	296
Total lease costs	$ 3,204	$ 6,236