Income Taxes (Components of Net Deferred Tax Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Deferred tax assets	$ 83.6	$ 233.8
Deferred tax liabilities	(543.7)	(533.8)
Net deferred tax liabilities	$ (460.1)	$ (300.0)