Fresh Start Accounting Fresh Start Adjustments - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2019	Sep. 30, 2019	Jul. 01, 2019
Fresh-Start Adjustment [Line Items]
Establishment of Successor goodwill			$ 178
Fresh start adjustment, Customer Related Intangibles			968
Fresh-Start adjustment, Technology based intangible			110
Fresh start adjustment, Trademark			141
Fresh Start Items, Right of Use Assets			$ 25
Favorable leasehold interest	$ 14	$ 14

Amount of goodwill at the balance sheet date after fresh-start adjustments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6918054&loc=SL2890621-112765

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