Long-Term Debt (Long-Term Debt) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, beginning balance	$ 17,400
Payments and Retirements	(2,483)
New Borrowings	2,599
Long-term debt, ending balance	17,400	$ 17,400	$ 17,516
Less: Debt Issuance Costs		(178)	(168)
Less: Debt Premium/(Discount)		(50)	(46)
Less: Current Portion		(814)	(994)
Total Long-Term Debt		16,358	$ 16,308
Interest Rate			8.72%
Secured Debt [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	5,246
Payments and Retirements		(828)
Long-term debt, ending balance	5,246	5,246	$ 5,711
Secured Debt [Member] \| Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	5,246
Payments and Retirements	(2,134)
New Borrowings	2,599
Long-term debt, ending balance	5,246	5,246	$ 5,711
Interest Rate			7.24%
Secured Debt [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	107
Payments and Retirements	(1)
Long-term debt, ending balance	107	107	$ 106
Interest Rate			8.36%
Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	11,297
Long-term debt, ending balance	11,297	11,297	$ 10,949
Unsecured Debt [Member] \| Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	11,297
Payments and Retirements	(348)
Long-term debt, ending balance	11,297	11,297	$ 10,949
Interest Rate			9.62%
Unsecured Debt [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	750
Long-term debt, ending balance	$ 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
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- 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.

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- Definition

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

+ References

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- Definition

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

+ References

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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

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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.

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- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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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

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