Accumulated Other Comprehensive Loss (Reclassification Out Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating expenses	$ 2.7			$ 21.3			$ 8.6	$ 32.3
Tax benefit	42.1			43.7			129.6	123.1
Total reclassifications for the period, net of tax	(118.1)	$ (124.4)	$ (125.0)	(126.3)	$ (127.8)	$ (102.4)	(367.5)	(356.5)
Non-cash pension settlement charge				15.9				15.9
Reclassification out of AOCI | Actuarial Losses Recognized
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating expenses	0.3			21.7			0.9	33.4
Tax benefit				(5.6)			(0.2)	(8.6)
Total reclassifications for the period, net of tax	$ 0.3			$ 16.1			$ 0.7	$ 24.8