Postretirement Plans (Schedule Of Changes In The Benefit Obligation, Plan Assets And Funded Status Of Both Pensions And OPB) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Company contribution			$ 3,500
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued pension plan liability, net	$ (16,276)	$ (15,323)
Pension Plans [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	71,424	80,393
Service cost	2	430	402
Interest cost	2,925	2,781	2,991
Amendments		(377)
Actuarial (gain)/loss	8,695	(6,352)
Settlement/curtailment/other	(756)	(730)
Gross benefits paid	(4,658)	(4,700)
Exchange rate adjustment	13	(21)
Ending balance	77,645	71,424	80,393
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance at fair value	56,102	64,011
Actual return on plan assets	10,851	(2,585)
Company contribution	16	16
Settlement payments	(756)	(764)
Benefits paid	(4,514)	(4,557)
Exchange rate adjustment	12	(19)
Ending balance at fair value	61,711	56,102	64,011
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Other assets	484	138
Other accrued liabilities	(142)	(137)
Accrued pension plan liability, net	(16,276)	(15,323)
Net amount recognized	(15,934)	(15,322)
Other Postretirement Benefits Plans [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	5,114	6,085
Service cost	77	94	106
Interest cost	196	194	229
Amendments	1	(58)
Actuarial (gain)/loss	127	(732)
Settlement/curtailment/other
Gross benefits paid	(474)	(487)
Subsidies	36	24
Exchange rate adjustment	3	(6)
Ending balance	5,080	5,114	6,085
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance at fair value	132	143
Actual return on plan assets	26	(3)
Company contribution	1	2
Plan participants' contributions	6	7
Benefits paid	(16)	(17)
Ending balance at fair value	149	132	$ 143
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Other accrued liabilities	(391)	(398)
Accrued retiree health care	(4,540)	(4,584)
Net amount recognized	$ (4,931)	$ (4,982)