Leases - Narrative (Details) $ in Millions	12 Months Ended
	Sep. 30, 2022 USD ($) renewal_option	Sep. 30, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Number of options to renew (or more) | renewal_option	1
Termination period	2 years
Operating right of use assets	$ 121.8	$ 125.3
Operating lease liabilities	$ 143.0	$ 146.6
Building | Minimum
Lessee, Lease, Description [Line Items]
Renewal term	3 years
Building | Maximum
Lessee, Lease, Description [Line Items]
Renewal term	10 years