Taxes - Effective Income Tax Reconcilliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income (loss) before income taxes
United States	$ (5,483)	$ 4,730	$ (441)
International	11,019	15,845	9,662
Income (Loss) Before Income Tax Expense	5,536	20,575	9,221
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Theoretical tax (at U.S. statutory rate of 21% - 2019 & 2018, 35% - 2017)	1,163	4,321	3,227
Effect of U.S. tax reform	3	(26)	(2,020)
Equity affiliate accounting effect	(687)	(1,526)	(1,373)
Effect of income taxes from international operations	2,196	3,132	(130)
State and local taxes on income, net of U.S. federal income tax benefit	(18)	162	39
Prior year tax adjustments, claims and settlements	192	(51)	(39)
Tax credits	(18)	(163)	(199)
Other U.S.	(140)	(134)	447
Total income tax expense (benefit)	$ 2,691	$ 5,715	$ (48)
Effective income tax rate	48.60%	27.80%	(0.50%)