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Income Taxes Income Taxes - Effective Tax Rates Differing From Prevailing Federal Corporate Income Tax Rates (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Reconciliation of Effective Tax Rates [Line Items] |  |  |  |  |  |  |  |  |  |  |
Tax on income from continuing operations at statutory rate |  |  |  |  |  |  |  |  | $ (92) | $ (38) | $ 57
Tax on income from continuing operations at statutory rate,tax rate |  |  |  |  |  |  |  |  | 21.00% | 21.00% | 21.00%
Tax-exempt interest |  |  |  |  |  |  |  |  | $ (2) | $ (3) | $ (7)
Tax-exempt interest, tax rate |  |  |  |  |  |  |  |  | 0.40% | 1.80% | (2.50%)
Derivative, Gain (Loss) on Derivative, Net | $ 12 | $ 7 | $ 2 | $ (70) | $ 12 | $ (10) | $ (35) | $ (16) | $ (50) | $ (50) | $ 7
Valuation allowance |  |  |  |  |  |  |  |  | $ 113 | $ 8 | $ 5
Valuation allowance, tax rate |  |  |  |  |  |  |  |  | (25.60%) | (4.40%) | 1.90%
Foreign taxes |  |  |  |  |  |  |  |  | $ 6 | $ 40 | $ 10
Foreign taxes, tax rate |  |  |  |  |  |  |  |  | (1.40%) | (22.10%) | 3.90%
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount |  |  |  |  |  |  |  |  | $ (29) | $ 28 | $ (60)
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Percent |  |  |  |  |  |  |  |  | 6.70% | (15.30%) | (22.00%)
Other, net |  |  |  |  |  |  |  |  | $ 0 | $ (2) | $ 1
Other, net, tax rate |  |  |  |  |  |  |  |  | 0.00% | 1.30% | 0.40%
Income tax expense (benefit) |  |  |  |  |  |  |  |  | $ (3) | $ 32 | $ 5
Effective Income Tax Rate Reconciliation, Percent |  |  |  |  |  |  |  |  | 0.70% | (17.70%) | 2.00%
Income Tax Reconciliation Tax Bankruptcy Adjustments |  |  |  |  |  |  |  |  | $ 0 | $ 0 | $ (2)
Effective income Tax Reconciliation Tax Bankruptcy Adjustments |  |  |  |  |  |  |  |  | 0.00% | 0.00% | (0.70%)
Variable Interest Entity, Primary Beneficiary [Member] | Income Loss On Variable Interest Entities [Member] |  |  |  |  |  |  |  |  |  |  |
Reconciliation of Effective Tax Rates [Line Items] |  |  |  |  |  |  |  |  |  |  |
Derivative, Gain (Loss) on Derivative, Net |  |  |  |  |  |  |  |  | $ (144) | $ (32) | $ 505
Variable Interest Entity, Primary Beneficiary [Member] | Currency Swaps [Member] | Income Loss On Variable Interest Entities [Member] |  |  |  |  |  |  |  |  |  |  |
Reconciliation of Effective Tax Rates [Line Items] |  |  |  |  |  |  |  |  |  |  |
Derivative, Gain (Loss) on Derivative, Net |  |  |  |  |  |  |  |  | (6) | (12) | 11
Variable Interest Entity, Primary Beneficiary [Member] | Interest Rate Swaps [Member] | Income Loss On Variable Interest Entities [Member] |  |  |  |  |  |  |  |  |  |  |
Reconciliation of Effective Tax Rates [Line Items] |  |  |  |  |  |  |  |  |  |  |
Derivative, Gain (Loss) on Derivative, Net |  |  |  |  |  |  |  |  | $ (138) | $ (20) | $ 493

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