Leases, Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating Lease Cost	$ 48.6	$ 29.4
Sublease Income	1.3	1.9
Total Lease Cost	47.3	27.5
Cash Paid for Amounts Included in the Measurement of Lease Liabilities	$ 30.8	$ 28.9
Weighted-Average Remaining Lease Term	6 years	7 years
Weighted-Average Discount Rate	4.37%	4.60%
Operating Lease Cost Prior to ASC 842			$ 29.2