Income Taxes (Income Before Tax) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
United States	$ 283.5	$ 347.6	$ 304.5
Foreign	14.2	16.0	8.9
Income before income taxes	$ 297.7	$ 363.6	$ 313.4

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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+ Details