Other Comprehensive Income (Loss) (Reclassification) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other–net, (income) expense	$ (9.3)	$ (13.9)	$ (95.3)	$ (43.1)
Total before tax	(1,465.9)	(41.7)	(2,197.0)	(1,407.4)
Tax benefit	(138.7)	(273.3)	(308.7)	(471.8)
Reclassifications from continuing operations (net of tax)	(1,327.2)	231.6	(1,888.3)	(935.6)
Reclassifications from discontinued operations (net of tax)	0.0	28.3	(3,680.5)	(21.9)
Net of tax	49.9	29.2	183.3	90.9
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications from continuing operations (net of tax)	49.9	28.5	99.3	89.5
Reclassifications from discontinued operations (net of tax)	0.0	0.7	84.0	1.4
Net of tax	49.9	29.2	183.3	90.9
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	(14.2)	(19.1)	(28.5)	(38.5)
Actuarial losses, net | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other–net, (income) expense	73.5	93.3	143.6	185.7
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	59.3	74.2	115.1	147.2
Tax benefit	12.3	15.6	23.4	30.9
Net of tax	47.0	58.6	91.7	116.3
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	$ 2.9	$ (30.1)	$ 7.6	$ (26.8)