Other Comprehensive Income (Loss) (Reclassification) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other–net, (income) expense	$ 59.3	$ 28.5
Total before tax	2,053.6	1,476.4
Tax benefit	(150.7)	(121.1)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications, net of tax	61.3	89.7
Defined Benefit Pension and Retiree Health Benefit Plans | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	74.2	108.8
Tax benefit	(15.6)	(22.9)
Total reclassifications, net of tax	58.6	85.9
Prior service benefits, net | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other–net, (income) expense	(13.0)	(13.8)
Actuarial losses, net | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other–net, (income) expense	87.2	122.6
Other, net of tax | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other–net, (income) expense	$ 2.7	$ 3.8