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

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

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