Fresh Start Accounting (Fresh Start - Disposition Of Liabilities Subject To Compromise) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Apr. 30, 2021
Successor [Member]
Liabilities subject to compromise
Reorganization Adjustments [Member]
Liabilities subject to compromise		(11,570)
Reorganization Adjustments [Member] | Successor [Member]
Liabilities subject to compromise		11,570
Reinstated on the Effective Date:
Accounts payable		(66)
Other current liabilities		(59)
Less: total liabilities reinstated		(125)
Amounts settled per the Plan of Reorganization
Issuance of take back debt		(750)
Payment for settlement of unsecured senior noteholders		(1,313)
Equity issued at emergence to unsecured senior noteholders		(4,108)
Total amounts settled		(6,171)
Gain on settlement of Liabilities Subject to Compromise		$ 5,274