Fresh Start Accounting (Fresh Start - Net Cash Payments) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Apr. 30, 2021
Cash and Cash Equivalents, at Carrying Value, Total	$ 322	$ 2,127
Reorganization Adjustments [Member]
Net proceeds from Incremental Exit Term Loan Facility			$ 220
Release of restricted cash from other assets to cash			8
Total sources			228
Payments of Excess to Unsecured senior notes holders			(1,313)
Payments of pre-petition accounts payable and contract cure payments			(62)
Payments of professional fees and other bankruptcy related costs			(22)
Total uses			(1,397)
Cash and Cash Equivalents, at Carrying Value, Total			$ (1,169)