Stock-Based Compensation (Nature Of Total Stock-Based Compensation) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 13.8	$ 14.2
Share-based Payment Arrangement, Expensed and Capitalized, Amount	14.1	14.5
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	10.9	10.2
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	2.1	3.2
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 1.1	$ 1.1