Fresh Start Accounting - Enterprise Value Reconciliation (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Feb. 09, 2021	Dec. 31, 2020
Reorganization, Chapter 11 [Line Items]
Enterprise Value			$ 4,851
Plus: Cash and cash equivalents	$ 130	$ 905	40	$ 279
Plus: Current liabilities	2,704	2,447	1,582
Plus: Asset retirement obligations (non-current portion)	323	349	236
Total assets	$ 15,468	$ 11,009	6,814
Restricted cash			86
Reorganization, Chapter 11, Fresh-Start Adjustment
Reorganization, Chapter 11 [Line Items]
Plus: Cash and cash equivalents			48
Plus: Current liabilities			0
Plus: Asset retirement obligations (non-current portion)			97
Plus: Other non-current liabilities			97
Total assets			359
Restricted cash			$ 8