Additional Financial Information (Cash and Cash Equivalents and Restricted Cash Balances) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents from continuing operations	$ 2,821	$ 3,701	$ 17,084	$ 19,223
Cash and cash equivalents from discontinued operations	0	0	21,481	1,946
Restricted cash in Prepaid and other current assets	1	1	2	3
Restricted cash in Other Assets	120	91	81	144
Cash and Cash Equivalents and Restricted Cash	$ 2,942	$ 3,793	$ 38,648	$ 21,316