Leases (Tables)

12 Months Ended

Sep. 30, 2022

Leases [Abstract]

Summary of ROU assets and lease liabilities

	September 30,
	2022		2021
ROU assets:
Other assets	$	7.5	$	9.7
Lease liabilities:
Other current liabilities	$	1.9	$	2.3
Other liabilities	6.6		8.6
Total liabilities	$	8.5	$	10.9

Lessee, operating lease, liability, maturity

Fiscal 2023	$	2.2
Fiscal 2024	2.2
Fiscal 2025	2.1
Fiscal 2026	2.1
Fiscal 2027	0.7
Total future minimum payments	9.3
Less: Implied interest	(0.8)
Total lease liabilities	$	8.5

Lease, costs and supplemental disclosures

	Year Ended September 30,
	2022	2021	2020
Operating lease expense	$3.8	$3.7	$4.0
Variable lease expense	0.9	0.7	0.6
Short-term lease expense	—	—	—
Weighted-average remaining lease term	4 years	5 years	6 years
Weighted-average incremental borrowing rate	4.6%	4.3%	4.2%