Fresh Start Accounting (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Apr. 30, 2021
Enterprise value	$ 12,500	$ 12,500
Decrease in right-of-use related to unfavorable lease contracts		4
Reduction in deferred tax assets		$ 1,500
Minimum [Member]
Enterprise value	10,500
Maximum [Member]
Enterprise value	$ 12,500

Amount of reorganization value related to present value of discounted cash flows of the emerging entity. Reorganization value is the amount attributed to the reconstituted entity, as well as the expected net realizable value of those assets that will be disposed before reconstitution occurs.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=84165509&loc=d3e56239-112766

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=124433192&loc=SL2890621-112765

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant