Leases - Schedule of Additional Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Sep. 30, 2024
Assets:
Operating lease assets	$ 410,521	$ 432,166
Finance lease assets	$ 70,300	$ 62,100
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Total lease assets	$ 480,800	$ 494,300
Current:
Operating lease liabilities	$ 129,700	$ 135,100
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities, Current	Accrued Liabilities, Current
Finance lease liabilities	$ 27,700	$ 25,500
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Long-Term Debt and Lease Obligation, Current	Long-Term Debt and Lease Obligation, Current
Total current lease liabilities	$ 157,400	$ 160,600
Non-current:
Operating lease liabilities	485,132	510,573
Finance lease liabilities	$ 42,200	$ 35,700
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Long-Term Debt and Lease Obligation	Long-Term Debt and Lease Obligation
Total non-current lease liabilities	$ 527,300	$ 546,300
Weighted average remaining lease term (in years):
Operating leases (in years)	6 years 1 month 6 days	6 years 2 months 12 days
Finance leases (in years)	2 years 9 months 18 days	2 years 7 months 6 days
Weighted average discount rates:
Operating leases (as percent)	5.20%	5.10%
Finance leases (as percent)	4.70%	4.40%