Pension And Postretirement Benefits (Pension And Postretirement Benefit Costs Included In Operating Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Net (credit) cost	$ (203)	$ (33)	$ (616)	$ (98)
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	305	282	904	846
Interest cost on benefit obligation	477	661	1,424	1,984
Expected return on assets	(832)	(849)	(2,484)	(2,549)
Amortization of prior service credit	(25)	(24)	(77)	(71)
Net (credit) cost	(75)	70	(233)	210
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	55	59	166	175
Interest cost on benefit obligation	242	365	725	1,094
Expected return on assets	(105)	(165)	(315)	(491)
Amortization of prior service credit	(320)	(362)	(959)	(1,086)
Net (credit) cost	$ (128)	$ (103)	$ (383)	$ (308)