Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Federal:
Current	$ 0.9	$ (47.3)
Deferred	3.2	32.3
State:
Current	0.0	(1.5)
Deferred	0.0	17.0
Foreign:
Current	3.3	0.6
Deferred	2.1	(0.8)
Total income tax expense	$ 9.5	$ 0.3