Fresh Start Accounting - Enterprise Value Reconciliation (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Feb. 09, 2021
Reorganization, Chapter 11 [Line Items]
Enterprise Value				$ 4,851
Plus: Cash and cash equivalents	$ 17	$ 905	$ 612	40
Plus: Current liabilities	4,241	2,447		1,582
Plus: Asset retirement obligations (non-current portion)	337	349		236
Plus: Other non-current liabilities				7
Assets	$ 13,899	$ 11,009		6,814
Restricted cash				86
Fresh Start Adjustments
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
Assets				359
Restricted cash				$ 8