Accumulated Other Comprehensive Loss (Reclassification Out Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating expenses, net	$ 0.8			$ 2.7			$ 2.9	$ 8.6
Tax benefit	40.0			42.1			114.5	129.6
Total reclassifications for the period, net of tax	(110.5)	$ (110.6)	$ (105.5)	(118.1)	$ (124.4)	$ (125.0)	(326.6)	(367.5)
Reclassification out of AOCI [Member] | Actuarial Losses Recognized [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating expenses, net	1.9			0.3			5.7	0.9
Tax benefit	(0.5)						(1.5)	(0.2)
Total reclassifications for the period, net of tax	$ 1.4			$ 0.3			$ 4.2	$ 0.7