Long-Term Debt (Long-Term Debt) (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, beginning balance	$ 17,516
Principal Payments and Retirements	(5)
Long-term debt, ending balance	17,511
Long-term debt	17,511	$ 17,511	$ 17,516
Less: Debt Issuance Cost		(68)	(168)
Less: Debt Discount		(48)	(46)
Less: Current Portion		(6,446)	(994)
Less: Debt subject to compromise		$ (10,949)
Total Long term debt			16,308
Interest rate		8.63%
Secured Debt [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	5,711
Long-term debt, ending balance	5,706
Long-term debt	5,711	$ 5,706	5,711
Secured Debt [Member] \| Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	5,711
Principal Payments and Retirements	(5)
Long-term debt, ending balance	5,706
Long-term debt	5,706	$ 5,706	5,711
Interest rate		7.17%
Secured Debt [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	106
Long-term debt, ending balance	106
Long-term debt	106	$ 106	106
Interest rate		8.37%
Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	10,949
Long-term debt, ending balance	10,949
Long-term debt	10,949	$ 10,949	10,949
Unsecured Debt [Member] \| Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	10,949
Long-term debt, ending balance	10,949
Long-term debt	10,949	$ 10,949	10,949
Interest rate		9.51%
Unsecured Debt [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	750
Long-term debt, ending balance	750
Long-term debt	$ 750	$ 750	$ 750
Interest rate		6.90%

Weighted average interest rate of long-term debt including debt issuance costs, premiums and or discounts.

No definition available.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount, after accumulated amortization, of debt discount (premium).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
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+ Details

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

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

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- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

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Period Type:	duration

- Details

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