Basis of Presentation (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Mar. 01, 2020	Jan. 01, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Held-to-maturity, Allowance for Credit Loss						$ 0.0
Proceeds from Interest Received	$ 9.8	$ 3.1
Accrued Investment Income Receivable	10.3
Accounts Receivable, Allowance for Credit Loss	146.1	74.2	$ 129.1			73.0	$ 72.4	$ 73.0
Off-Balance Sheet, Credit Loss, Liability						0.0
Deferred tax liability, net	(32.2)					(26.7)
Retained Earnings (Accumulated Deficit)	912.5					953.6
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Debt Securities, Held-to-maturity, Allowance for Credit Loss					$ 0.0
Accounts Receivable, Allowance for Credit Loss			2.1		103.0	0.0	0.0	0.0
Off-Balance Sheet, Credit Loss, Liability	2.3	$ 0.0	$ 0.2	$ 0.0	2.3	$ 0.0	$ 0.0	$ 0.0
Deferred tax liability, net					(18.5)
Retained Earnings (Accumulated Deficit)					929.5
Cumulative Effect, Period of Adoption, Adjustment [Member]
Debt Securities, Held-to-maturity, Allowance for Credit Loss					0.0
Accounts Receivable, Allowance for Credit Loss	$ 30.0				30.0
Off-Balance Sheet, Credit Loss, Liability					2.3
Deferred tax liability, net					(8.2)
Retained Earnings (Accumulated Deficit)					$ (24.1)