Stock Based Compensation (PSU Activity) (Details) - Long-Term Equity Incentive Plan - Performance Share Units - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 40.3	$ 24.8	$ 31.8
Income tax benefit	(5.8)	(3.7)	(3.3)
Share-based compensation expense, net of tax	$ 34.5	$ 21.1	$ 28.5