Taxes (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance [Line Items]
Decrease in income tax benefit	$ 1,681
Income tax expense (benefit)	48	$ 1,729	$ (132)
Effect of change in U.S. tax rate	$ 2,020
Effective tax rate	(0.50%)	80.00%	2.70%
Loss carry forward	$ 16,102
Tax credit carryforward	1,379
Carry forward amount of foreign tax credit with expiration dates	11,872	$ 10,976
Undistributed earnings of international consolidated subsidiaries and affiliates for which no deferred income tax provision has been made for future remittances	$ 57,300
Percentage of impact of unrecognized tax benefits on effective tax rate if subsequently recognized	81.00%
Unrecognized tax benefits	$ 4,828	3,031	$ 3,042	$ 3,552
Income tax accruals for anticipated interest and penalty obligations	178	424
Income tax benefit expense associated with interest and penalties	(161)	$ 38	$ 195
Property, Plant and Equipment
Valuation Allowance [Line Items]
Decrease in deferred tax liabilities	5,700
Asset Retirement Obligation
Valuation Allowance [Line Items]
Decrease in deferred tax assets	$ 2,300