Leases - Other pertinent information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating cash flows used for operating leases	$ 42,013	$ 37,758
Right-of-use assets obtained in exchange for lease obligations
Finance leases	10,333	6,083
Operating leases	$ 25,690	$ 34,169