Leases - Balance Sheet Location (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
Operating Leases:
Operating lease asset	$ 112.3	$ 121.9
Operating lease liabilities - current	15.5	14.8
Operating lease liabilities	102.3	111.9
Total Operating Lease Liabilities	$ 117.8	$ 126.7
Weighted-average remaining lease term (in years)	16 years 3 months 18 days	16 years 2 months 12 days
Weighted-average discount rate	4.10%	4.20%
Finance Leases:
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, plant and equipment, net	Property, plant and equipment, net
Property, plant and equipment, net	$ 37.2	$ 43.9
Current portion of capital leases	$ 2.3	$ 1.7
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term debt	Long-term debt
Long-term debt	$ 42.0	$ 44.1
Total Finance Lease Liabilities	$ 44.3	$ 45.8
Weighted Average remaining lease term (in years)	19 years 9 months 18 days	20 years 4 months 24 days
Weighted-average discount rate	6.70%	6.70%