Leases, Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating Lease Cost	$ 16.4	$ 19.6	$ 35.2
Sublease Income	1.5	1.1	1.0
Total Lease Cost	14.9	18.5	34.2
Cash Paid for Amounts Included in the Measurement of Lease Liabilities	$ 20.3	$ 23.1	$ 29.9
Weighted-Average Remaining Lease Term	5 years	6 years	6 years
Weighted-Average Discount Rate	4.85%	4.32%	4.45%