Pension And Other Postretirement Benefits (Long-Term Rates Of Pension And Other Postretirement Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Total recorded in other comprehensive income	$ (1,657)	$ (1,279)	$ (2,287)
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.80%	4.25%	4.25%
Long-term rate of return on funded assets	6.00%	6.50%	6.50%
Long-term rate of compensation increase	5.75%	5.75%	5.75%
Service cost	$ 819	$ 784	$ 810
Interest cost	721	798	793
Expected return on plan assets	(727)	(775)	(726)
Amortization of actuarial loss/(gain)	362	438	492
Amortization of prior service cost	5	5	6
Net pension enhancement and curtailment/settlement cost	268	609	319
Net periodic benefit cost	1,448	1,859	1,694
Net actuarial loss/(gain)	479	(324)	27
Amortization of actuarial (loss)/gain	(630)	(1,047)	(811)
Amortization of prior service (cost)/credit	(5)	(5)	(6)
Total recorded in other comprehensive income	(156)	(1,376)	(790)
Total recorded in net periodic benefit cost and other comprehensive income, before tax	$ 1,292	$ 483	$ 904
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.80%	3.00%	3.60%
Long-term rate of return on funded assets	4.70%	5.20%	5.25%
Long-term rate of compensation increase	4.30%	4.00%	4.80%
Service cost	$ 608	$ 596	$ 585
Interest cost	754	772	844
Expected return on plan assets	(951)	(1,000)	(927)
Amortization of actuarial loss/(gain)	409	476	536
Amortization of prior service cost	46	47	54
Net pension enhancement and curtailment/settlement cost	44	19	2
Net periodic benefit cost	910	910	1,094
Net actuarial loss/(gain)	(66)	(191)	(156)
Amortization of actuarial (loss)/gain	(453)	(495)	(538)
Prior service cost/(credit)	98	111	32
Amortization of prior service (cost)/credit	(46)	(47)	(54)
Foreign exchange rate changes	(356)	559	(108)
Total recorded in other comprehensive income	(823)	(63)	(824)
Total recorded in net periodic benefit cost and other comprehensive income, before tax	$ 87	$ 847	$ 270
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.80%	4.25%	4.25%
Long-term rate of return on funded assets	6.00%	6.50%	6.50%
Long-term rate of compensation increase	5.75%	5.75%	5.75%
Service cost	$ 152	$ 129	$ 153
Interest cost	301	317	344
Expected return on plan assets	(23)	(24)	(25)
Amortization of actuarial loss/(gain)	116	96	153
Amortization of prior service cost	(40)	(33)	(30)
Net periodic benefit cost	506	485	595
Net actuarial loss/(gain)	(594)	215	(555)
Amortization of actuarial (loss)/gain	(116)	(96)	(153)
Amortization of prior service (cost)/credit	40	33	30
Foreign exchange rate changes	(8)	8	5
Total recorded in other comprehensive income	(678)	160	(673)
Total recorded in net periodic benefit cost and other comprehensive income, before tax	$ (172)	$ 645	$ (78)