Basis of Presentation and Significant Accounting Policies, Voluntary Reorganization under Chapter 11 Cases - Schedule of Reorganization Items (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Reorganizations [Abstract]
Professional fees	$ 44
Rejection of executory contracts approved by Bankruptcy Court	16
DIP Facility costs	5
Total reorganization items, net	$ 65	$ 0

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

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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
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-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 discharge of claims and liabilities upon emergence from bankruptcy.

+ 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
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56145-112766

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
-Paragraph 9
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Amount of reorganization items related to legal and advisory professional fees related to entities in bankruptcy.

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Total amount of reorganization items.

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