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Investments - Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments (Details) - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2019 | Mar. 31, 2018
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | $ 186 | $ (92)
Realized — impairments |  | (2) | (1)
Total realized gains (losses) on securities |  | 184 | (93)
Net of tax |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | 147 | (72)
Realized — impairments |  | (2) | (1)
Total realized gains (losses) on securities |  | 145 | (73)
Change in unrealized |  | 381 | (277)
Total pretax |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | 186 | (92)
Realized — impairments |  | (2) | (1)
Total realized gains (losses) on securities |  | 184 | (93)
Change in unrealized |  | 483 | (351)
Fixed maturities |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | 3 | (1)
Realized — impairments |  | (3) | (1)
Total realized gains (losses) on securities |  | 0 | (2)
Change in unrealized |  | 853 | (599)
Equity securities |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | 182 | (95)
Realized — impairments |  | 0 | 0
Total realized gains (losses) on securities |  | 182 | (95)
Change in unrealized |  | 0 | 0
Other, Including DPAC and reserves related to the annuity business |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments | [1] | 1 | 4
Realized — impairments | [1] | 1 | 0
Total realized gains (losses) on securities | [1] | 2 | 4
Change in unrealized | [1] | (370) | 248
Tax effects |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | (39) | 20
Realized — impairments |  | 0 | 0
Total realized gains (losses) on securities |  | (39) | 20
Change in unrealized |  | $ (102) | $ 74
[1] | Primarily adjustments to deferred policy acquisition costs and reserves related to the annuity business.

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- Definition Change in unrealized appreciation depreciation. + References No definition available. + Details
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- Definition Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments. + References No definition available. + Details
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- Definition Amount of realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI). + References No definition available. + Details
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- Definition Amount of realized gain (loss) on investment in marketable security, excluding other-than-temporary impairment (OTTI). + References No definition available. + Details
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- Definition The amount of other than temporary impairment losses on investments in debt and equity securities categorized as Available-for-sale which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) on equity securities, credit losses on investments in debt securities, and when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis. + References No definition available. + Details
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