Pensions and Postretirement Benefits Other than Pensions (Components of Net Periodic Postretirement Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Total	$ (8.2)	$ (8.1)
Postretirement Benefit Costs [Member]
Service cost	0.8	0.9
Interest cost	4.3	4.5
Net amortization of prior service gains	(2.2)	(2.2)
Net amortization of plan net actuarial losses	0.0	0.0
Total	2.9	3.2
Postretirement Benefit Costs [Member] | Segment, Continuing Operations [Member]
Total
Postretirement Benefit Costs [Member] | Discontinued Operations [Member]
Total	$ 0.9	$ 1.1