Emergence From The Chapter 11 Cases (Schedule Of Liabilities Subject To Compromise) (Details) $ in Millions	Dec. 31, 2020 USD ($)
Emergence From The Chapter 11 Cases [Abstract]
Accounts payable	$ 57
Other current liabilities	62
Accounts payable and other current liabilities	119
Debt subject to compromise	10,949
Accrued interest on debt subject to compromise	497
Long-term debt and accrued interest	11,446
Liabilities subject to compromise	$ 11,565