Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Leases [Abstract]
Operating lease cost	$ 571	$ 1,779
Less: sublease income	(156)	(393)
Variable lease cost	86	265
Short-term lease cost	148	496
Total lease cost	$ 649	$ 2,147