Pension And Other Benefit Programs (Schedule Of Net Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets as of beginning of period	$ 1,512.9
Fair value of plan assets as of end of period	1,529.7	$ 1,512.9
Defined Benefit Pension Plans [Member] | U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation as of beginning of period	1,522.4	1,918.1
Service cost	8.6	10.1
Interest cost	48.1	69.8
Partial settlement	(58.1)
Actuarial loss (gain)	77.2	0.6
Benefits paid	(103.2)	(111.0)
Merger of Tectum Plan	5.1
Separation of AFI		(365.2)
Benefit obligation as of end of period	1,500.1	1,522.4
Fair value of plan assets as of beginning of period	1,512.9	1,837.2
Actual return on plan assets	170.8	144.7
Employer contribution	3.9	4.2
Partial settlement	(58.1)
Benefits paid	(103.2)	(111.0)
Merger of Tectum Plan	3.4
Separation of AFI		(362.2)
Fair value of plan assets as of end of period	1,529.7	1,512.9
Funded status of the plans	29.6	(9.5)
Defined Benefit Pension Plans [Member] | Non-U.S. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation as of beginning of period	2.5	2.5
Service cost	0.0	0.0
Interest cost	0.0	0.1
Foreign currency translation adjustment	0.4	(0.2)
Actuarial loss (gain)	(0.1)	0.2
Benefits paid	(0.1)	(0.1)
Benefit obligation as of end of period	2.7	2.5
Employer contribution	0.1	0.1
Benefits paid	(0.1)	(0.1)
Funded status of the plans	(2.7)	(2.5)
U.S. Defined-Benefit Retiree Health And Life Insurance Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation as of beginning of period	93.1	190.3
Service cost	0.4	0.4
Interest cost	3.0	4.7
Plan participants' contributions	2.8	3.2
Plan amendments	(1.1)
Actuarial loss (gain)	(1.3)	(7.7)
Benefits paid	(10.3)	(11.5)
Separation of AFI		(86.3)
Benefit obligation as of end of period	86.6	93.1
Fair value of plan assets as of beginning of period	0.0	0.0
Employer contribution	7.5	8.3
Plan participants' contributions	2.8	3.2
Benefits paid	(10.3)	(11.5)
Fair value of plan assets as of end of period	0.0	0.0
Funded status of the plans	$ (86.6)	$ (93.1)