Leases - Lessee Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023	Mar. 31, 2023
Lease assets:
Operating lease right-of-use assets	$ 243,752	$ 234,388	$ 234,287
Financing lease assets	2,094	2,178	1,289
Total lease assets	245,846	236,566	235,576
Current:
Operating lease liabilities	55,658	57,182	53,921
Financing lease liabilities	583	530	282
Total current lease liabilities	56,241	57,712	54,203
Non-current:
Operating lease liabilities	197,285	193,187	191,874
Financing lease liabilities	1,626	1,715	1,024
Total non-current lease liabilities	198,911	194,902	192,898
Total lease liabilities	$ 255,152	$ 252,614	$ 247,101
Finance Lease, Other Assets, Statement of Financial Position [Extensible Enumeration]	Other Assets, Noncurrent	Other Assets, Noncurrent	Other Assets, Noncurrent
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accounts payable, accrued expenses and other current liabilities	Accounts payable, accrued expenses and other current liabilities	Accounts payable, accrued expenses and other current liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent