Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating lease cost:
Operating lease cost	$ 19,066	$ 17,495
Variable lease cost	4,215	3,852
Total operating lease cost	23,281	21,347
Financing lease cost:
Amortization of financing lease assets	151	19
Interest on financing lease liabilities	65	11
Total financing lease cost	216	30
Total lease cost	23,497	21,377
Sublease income	$ 1,100	$ 800
Weighted-average remaining lease term (years):
Operating leases	4 years 10 months 9 days	5 years 2 months 15 days
Financing leases	3 years 5 months 1 day	4 years 10 days
Weighted-average discount rate:
Operating leases	8.53%	8.36%
Financing leases	11.14%	11.14%