Pensions and Postretirement Benefits Other than Pensions (Components of the Company's Pension-Related Costs) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Total			$ (9.7)	$ (14.4)
Pension Costs [Member]
Service cost	$ 17.9	$ 17.9	35.8	35.7
Interest cost	26.9	27.0	53.9	54.0
Expected return on plan assets	(36.7)	(35.2)	(73.6)	(70.4)
Net amortization of prior service costs	1.0	0.9	2.1	1.9
Net amortization of plan net actuarial losses	12.5	13.5	25.0	27.1
Net periodic pension benefit cost	21.6	24.1	43.2	48.3
Net curtailment loss	(1.2)	0.0	(1.2)	(2.3)
Total	22.8	24.1	44.4	50.6
Pension Costs [Member] | Segment, Continuing Operations [Member]
Total
Pension Costs [Member] | Discontinued Operations [Member]
Total	$ 2.1	$ 2.4	$ 4.2	$ 4.8