Leases - Additional Information (Details)	12 Months Ended
	Sep. 30, 2025 USD ($) ft²
Lessee Lease Description [Line Items]
Boston Lease Square Feet | ft²	250,000
Boston lease year one payments	$ 11,000,000
Boston lease per square foot annual increase	1
Boston lease annual increase	300,000
Boston lease building operating cost amount estimate year one	8,200,000
Asset Impairment Charges	$ 15,600,000
Leases not yet commenced, Term of contract	5 years
Future lease payments	$ 7,400,000
Right-of-Use Assets [Member]
Lessee Lease Description [Line Items]
Asset Impairment Charges	$ 12,800,000