Income Taxes (Components of Income from Continuing Operations Before Income Taxes and Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income from continuing operations before income taxes	$ 41.1	$ 144.0	$ 521.3
Current	32.6	73.7	77.5
Deferred	(25.0)	(46.5)	23.8
Total income tax expense	$ 7.6	$ 27.2	$ 101.3