Accumulated Other Comprehensive Loss (Reclassification Out Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating expenses, net	$ 1.7		$ 3.1		$ 2.1	$ 5.9
Tax benefit	37.7		43.6		74.5	87.5
Total reclassifications for the period, net of tax	(110.6)	$ (105.5)	(124.4)	$ (125.0)	(216.1)	(249.4)
Reclassification out of AOCI [Member] | Actuarial Losses Recognized [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating expenses, net	2.3		0.3		3.8	0.6
Tax benefit	(0.6)		(0.1)		(1.0)	(0.2)
Total reclassifications for the period, net of tax	$ 1.7		$ 0.2		$ 2.8	$ 0.4