Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Decrease in income tax expense	$ 3,024
Effective tax rate	48.60%	27.80%	(0.50%)
Increase in deferred tax liabilities	$ 2,500
Loss carry forward	13,419
Tax credit carryforward	1,058
Carry forward amount of foreign tax credit with expiration dates	9,840
Tax Cuts and Jobs Act of 2017, existing undistributed accumulated earnings of foreign subsidiary	$ 52,500
Percentage of impact of unrecognized tax benefits on effective tax rate if subsequently recognized	81.00%
Unrecognized tax benefits	$ 4,987	$ 5,070	$ 4,828	$ 3,031
Income tax accruals for anticipated interest and penalty obligations	30	33
Income tax benefit expense associated with interest and penalties	$ (3)	$ 8	$ (161)