Postretirement Plans (Schedule Of Amounts Recognized In Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 20,871	$ 21,321
Prior service costs/(credits)	(1,195)	385
Total recognized in Accumulated other comprehensive loss	19,676	21,706
Other Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	781	877
Prior service costs/(credits)	(397)	(512)
Total recognized in Accumulated other comprehensive loss	$ 384	$ 365