Leases - Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Lease, Cost [Abstract]
Operating lease costs	$ 12,435	$ 9,396
Amortization of assets	620	182
Interest on lease liabilities	40	5
Total finance lease costs	660	187
Total operating and finance lease costs	13,095	9,583
Variable lease cost	3,251	3
Short-term lease costs	1,920	1,411
Total lease costs	$ 18,266	$ 10,997