Retirement Plans (Schedule Of Net Periodic Benefit Cost For Pension And Postretirement Benefit Plans) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 3	$ 9	$ 12	$ 25
Interest cost		9	13	32	39
Expected return on plan assets		(14)	(14)	(40)	(44)
Amortization of prior service cost	[1]	1	1	2	3
Net actuarial loss	[1]	6	5	19	15
Net periodic benefit cost	[2]	$ 5	$ 14	25	38
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost	[1]			(1)	(1)
Net periodic benefit cost	[2]			$ (1)	$ (1)

[1] These net periodic benefit costs were reclassified out of other comprehensive earnings in the current period.

[2] Net periodic benefit cost is a component of G&A in the accompanying consolidated comprehensive statements of earnings.