Accumulated Other Comprehensive Loss (Reclassifications Out Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating expenses	$ 7.5	$ 6.6
Tax benefit	8.7	13.0
Total reclassifications for the period, net of tax	(21.5)	(34.4)
Reclassification out of AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating expenses	7.4	5.0
Tax benefit	(1.9)	(1.3)
Total reclassifications for the period, net of tax	5.5	3.7
Reclassification out of AOCI | Actuarial Losses Recognized
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating expenses	7.4	5.0
Tax benefit	(1.9)	(1.3)
Total reclassifications for the period, net of tax	$ 5.5	$ 3.7