Leases (Tables)

12 Months Ended

Sep. 30, 2025

Leases [Abstract]

Summary of ROU assets and lease liabilities

	September 30,
	2025		2024
ROU assets:
Other assets	$	26.2	$	5.8
Lease liabilities:
Other current liabilities	$	2.6	$	2.2
Other liabilities	26.9		4.3
Total liabilities	$	29.5	$	6.5

Lessee, operating lease, liability, maturity

Fiscal 2026	$	3.2
Fiscal 2027	4.1
Fiscal 2028	5.3
Fiscal 2029	5.4
Fiscal 2030	5.5
Thereafter	34.8
Total future minimum payments	58.3
Less: Implied interest	19.2
Less: Tenant improvement allowance	9.6
Total lease liabilities	$	29.5

Lease, costs and supplemental disclosures

	Year Ended September 30,
	2025	2024	2023
Total operating lease expense	$3.9	$3.4	$3.1
Variable lease expense	1.3	1.0	0.9
Weighted-average remaining lease term	10 years	4 years	4 years
Weighted-average incremental borrowing rate	7.0%	4.9%	4.8%