Leases - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	May 31, 2025	Dec. 31, 2024
Lessee, Lease, Description [Line Items]
Initial term of lease (in years)	10 years
Renewable term of lease (in years)				5 years
Total lease liabilities	$ 309,808
Impairment charges			$ 4,300
Operating lease right of use asset non cash	66,200	$ 55,300	$ 66,500
Corporate Office Lease, Two Five-Year Extension Options
Lessee, Lease, Description [Line Items]
Initial term of lease (in years)					13 years
Total lease liabilities	13,100
Estimated future minimum sublease payments	$ 6,400