Debt, Interest Income, Expense and Other Finance Costs - Schedule of Debt (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Finance Leases	$ 20.0	$ 18.2
Total debt	523.5	524.7
Less: Current maturities of long-term debt and finance leases	26.6	22.9
Long-term debt	496.9	501.8
Other
Debt Instrument [Line Items]
Long-term debt	3.3	3.3
Term Loans | Term Loans
Debt Instrument [Line Items]
Long-term debt	$ 500.1	$ 503.2