Pension and Other Benefit Programs (Schedule of Periodic Benefit Costs (Credits) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
U.S. Defined-Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost of benefits earned during the period	$ 1.4	$ 2.2	$ 4.3	$ 6.4
Interest cost on projected benefit obligation	11.5	12.1	34.6	37.0
Expected return on plan assets	(24.0)	(24.7)	(72.0)	(74.3)
Amortization of prior service (credit) cost		0.4		1.1
Amortization of net actuarial (gain) loss	5.0	4.3	15.0	12.8
Partial settlement		20.8		20.8
Net periodic pension\postretirement (credit) cost	(6.1)	15.1	(18.1)	3.8
Retiree Health And Life Insurance Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost of benefits earned during the period		0.1	0.1	0.3
Interest cost on projected benefit obligation	0.6	0.7	1.9	2.2
Amortization of net actuarial (gain) loss	(1.4)	(0.9)	(4.2)	(2.7)
Net periodic pension\postretirement (credit) cost	$ (0.8)	$ (0.1)	$ (2.2)	$ (0.2)