Leases Leases - Supplemental Balance Sheet Information (Details) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease right-of-use assets	$ 26.1
Accrued expenses	4.9
Other long-term liabilities	21.4
Total operating lease liabilities	26.3
Property and equipment, at cost	111.8
Accumulated depreciation	(30.5)
Property and equipment, net	81.3
Current maturities of long-term debt	29.7
Long term debt, less current maturities	22.9
Total finance lease liabilities	$ 52.6	$ 52.6