| **Income Taxes (Differences Between The 35 Percent Statutory Income Tax Rate And Effective Income Tax Rate) (Details) - USD ($) $ in Millions** | 12 Months Ended |
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| **Income Tax Disclosure [Abstract]**                                                                                                            |            |   |   |
| Tax at statutory rate:                                                                                                                          | $ 256           | $ 284 | $ 308 |
| Tax at statutory rate (percentage):                                                                                                             | 35.00%          | 35.00% | 35.00% |
| **Increase (decrease) resulting from:**                                                                                                         |            |   |   |
| Tax-exempt income from municipal bonds                                                                                                          | $ (36)          | $ (34) | $ (33) |
| Dividend received exclusion                                                                                                                     | (34)            | (33) | (32) |
| Deferred tax benefit due to tax rate change                                                                                                     | (495)           | 0 | 0 |
| Other                                                                                                                                           | (6)             | 4 | 4 |
| Total provision (benefit) for income taxes                                                                                                      | $ (315)         | $ 221 | $ 247 |
| **Tax at statutory rate:**                                                                                                                      |            |   |   |
| Tax-exempt income from municipal bonds (percentage)                                                                                             | (4.90%)         | (4.20%) | (3.70%) |
| Dividend received exclusion (percentage)                                                                                                        | (4.70%)         | (4.10%) | (3.60%) |
| Deferred tax benefit due to tax rate change                                                                                                     | (67.80%)        | 0.00% | 0.00% |
| Other (percentage)                                                                                                                              | (0.80%)         | 0.50% | 0.30% |
| Effective tax, percentage                                                                                                                       | (43.20%)        | 27.20% | 28.00% |

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the income tax rates.
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deduction for dividend.
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to income (loss) exempt from income taxes.
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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) in the income tax rates.
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