Leases Leases - Maturities of Operating and Financing Lease Liabilities (Details) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Sep. 30, 2019
Operating Leases
2020		$ 5.6
2021		5.0
2022		3.3
2023		2.5
2024		2.0
Thereafter		21.5
Total lease payments		39.9
Less: Imputed interest		(13.6)
Present value of lease liabilities		26.3
Finance Leases
2020		31.5
2021		17.5
2022		4.8
2023		1.3
2024		0.7
Thereafter		0.0
Less: Imputed interest		55.8
Less: Imputed interest		(3.2)
Present value of lease liabilities	$ 52.6	$ 52.6