Chapter 11 Filing And Other Related Matters (Schedule Of Reorganization Items) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Chapter 11 Filing And Other Related Matters [Abstract]
Write-off debt issuance costs and original issue net discount on debt subject to compromise	$ 93
Debtor-in-possession financing costs	121
Secured Creditor Settlement	58
Professional fees and other bankruptcy related costs	137
Reorganization items, net	$ 409

Debtor Reorganization Items, Lender Settlement

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Amount of reorganization items related to debtor-in-possession facility financing costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 45
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=116635682&loc=d3e55730-112764

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 10
-Section 55
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56145-112766

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Amount of reorganization items related to legal and advisory professional fees related to entities in bankruptcy.

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Amount of write-off of debt issuance costs and debt discounts related to prepetition debt obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 3
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Total amount of reorganization items.

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