Income Taxes (Gross Unrecognized Tax Benefits Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance of liability as of January 1,	$ 7.6	$ 10.3	$ 11.4
Increase as a result of tax positions taken during a prior year	0.0	0.0	0.0
Decrease as a result of tax positions taken during a prior year	(0.2)	0.0	0.0
Increase as a result of tax positions taken during the current year	0.5	0.4	0.2
Decrease as a result of settlements with taxing authorities	(0.1)	0.0	(0.8)
Reduction as a result of a lapse of the statute of limitations	(5.2)	(3.1)	(0.5)
Other	13.9	0.0	0.0
Balance of liability as of December 31,	$ 16.5	$ 7.6	$ 10.3