Leases - Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease Cost:
Amortization of Right-of-Use Assets - Finance Leases	$ 0.3	$ 0.7
Operating Lease Cost	20.9	20.7
Short-Term Lease Cost	4.6	0.1
Total Expense	25.8	21.5
Less: Sublease Income	0.0	0.1
Total Lease Cost	$ 25.8	$ 21.4