Leases - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021	Feb. 28, 2019
Lessee Lease Description [Line Items]
Lease expiration date			2037
Payments to be received as sublease income	$ 2,900		$ 2,900			$ 9,100
Operating right-of-use lease assets	149,801		149,801		$ 152,337
Operating lease, liability	203,990		203,990
Lease Cost	10,741	$ 11,520	21,515	$ 22,762
Operating cash flows from operating leases	9,248	14,016	25,113	28,076
Facility Closures and Related Costs
Lessee Lease Description [Line Items]
Operating lease liability, net restructured facilities	1,700		1,700		$ 3,600
Operating right-of-use lease assets	300		300
Operating lease, liability	2,000		2,000
Operating cash flows from operating leases	600	$ 2,500	1,300	$ 6,300
Sublease Income Committed
Lessee Lease Description [Line Items]
Sublease income assumed	$ 700		$ 700