Income Taxes, Schedule of Income Taxes Paid (Refunded), Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Income Taxes Paid, Net
Income taxes paid (refunded), net	$ 203	$ (116)		$ 1,361
U.S. [Member]
Income Taxes Paid, Net
Income taxes paid (refunded), net	130	(298)	[1]	1,016
U.S. [Member] | Internal Revenue Service (IRS) [Member]
Income Taxes Paid, Net
Refund received, including interest, associated with income tax audit		348
International [Member]
Income Taxes Paid, Net
Income taxes paid (refunded), net	$ 73	$ 182		$ 345

[1] This amount includes a refund of $348 million, including interest, that we received related to the settlement of the combined audit of our U.S. federal income tax returns for 2010 and 2011. See “Tax Returns Under Audit – U.S. Federal” on page 119.