Income Taxes, Details of the Tax Reform Adjustment (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Income Tax Disclosure [Abstract]
Income tax benefit from the remeasurement of U.S. deferred income tax assets and liabilities	$ (2,643)
Tax on the deemed repatriation of the accumulated earnings and profits of our international subsidiaries	734
Recognition of foreign withholding tax, net of U.S. federal tax benefit	47
Deductibility of certain executive compensation expense	0
Income tax expense associated with the statutory income tax rate differential on accrual to return adjustments that may be identified upon completion of our U.S. federal income tax return in 2018	0
Foreign tax credit available to offset the tax on deemed repatriation of the accumulated earnings and profits of our international subsidiaries	0
Estimated Tax Reform benefit	$ (1,862)