Pensions and Postretirement Benefits Other Than Pensions (Schedule of Net Periodic Postretirement Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net periodic benefit cost after net curtailment and settlement (gains) losses	$ (39.3)	$ (21.9)	$ (31.0)
Postretirement Benefit Costs [Member]
Service cost	2.6	2.8	3.1
Interest cost	14.8	14.4	15.7
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(0.3)	(3.8)	(8.6)
Plan net actuarial losses, net amortization of	(10.9)	(1.0)	0.1
Net periodic benefit cost	6.2	12.4	10.3
Net periodic benefit cost after net curtailment and settlement (gains) losses	6.2	12.4	10.3
Segment, Continuing Operations [Member] | Postretirement Benefit Costs [Member]
Net periodic benefit cost after net curtailment and settlement (gains) losses
Segment, Discontinued Operations [Member] | Postretirement Benefit Costs [Member]
Net periodic benefit cost after net curtailment and settlement (gains) losses	0.4	2.3	1.6
Operating Income (Loss) [Member] | Segment, Continuing Operations [Member] | Postretirement Benefit Costs [Member]
Net periodic benefit cost after net curtailment and settlement (gains) losses	2.6	2.8	3.1
Other Nonoperating Income (Expense) [Member] | Segment, Continuing Operations [Member] | Postretirement Benefit Costs [Member]
Net periodic benefit cost after net curtailment and settlement (gains) losses	$ 3.2	$ 7.3	$ 5.6