Revenues (Changes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Changes to contract liabilities
Total contract liabilities, at beginning of period	$ 456	$ 529
Decrease due to recognition of revenues for goods and services	(149)	(184)
Increase due to goods and services transferred over time	41	111
Total contract liabilities, at end of period	$ 348	$ 456