Stock-Based Compensation (Nature Of Total Stock-Based Compensation) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 15.1	$ 13.8
Share-based Payment Arrangement, Expensed and Capitalized, Amount	15.3	14.1
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	12.1	10.9
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	2.1	2.1
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 1.1	$ 1.1