Pensions and Postretirement Benefits Other than Pensions (Components of Net Periodic Postretirement Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Total	$ 1.2	$ (5.7)
Postretirement Benefit Costs [Member]
Service cost	0.5	0.5
Interest cost	1.7	1.4
Net amortization of plan net actuarial losses	(1.4)	(0.5)
Total	0.8	1.4
Postretirement Benefit Costs [Member] | Continuing Operations [Member]
Total
Postretirement Benefit Costs [Member] | Discontinued Operations [Member]
Total	0.0	0.3
Operating Income (Loss) [Member] | Postretirement Benefit Costs [Member] | Continuing Operations [Member]
Total	0.5	0.5
Other Nonoperating Income (Expense) [Member] | Postretirement Benefit Costs [Member] | Continuing Operations [Member]
Total	$ 0.3	$ 0.6