Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Cash Flow, Operating Activities, Lessee [Abstract]
Operating cash flows from operating leases	$ 2,535	$ 2,067	$ 4,998	$ 3,874
Operating cash flows from finance leases	12	26	27	55
Financing cash flows from finance leases	$ 308	$ 293	$ 612	$ 583