Leases - Lessee Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020	Jun. 30, 2020
Leases [Abstract]
Right-of-use asset	$ 185,467	$ 183,809	$ 204,591
Lease liability, current	47,241	49,742	48,840
Lease liability, non-current	149,342	153,040	167,716
Present value of operating lease liabilities	$ 196,583	$ 202,782	$ 216,556