Supplemental Cash Flow Statement Disclosures (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash, Cash Equivalents and Restricted Cash
Cash and cash equivalents	$ 563	$ 1,366	$ 1,798
Current restricted cash	$ 16	$ 15	8
Location of current restricted cash	Other current assets	Other current assets
Total cash, cash equivalents and restricted cash	$ 579	$ 1,381	$ 1,806	$ 728
Other Non-cash items
PP&E acquired but not yet paid	$ 540	$ 409