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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, 2020 | Mar. 31, 2019
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | $ (505) | $ 186
Realized gains (losses) on securities |  | (551) | 184
Net of tax |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | (399) | 147
Realized — impairments |  | (36) | (2)
Realized gains (losses) on securities |  | (435) | 145
Change in unrealized |  | (846) | 381
Total pretax |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | (505) | 186
Realized — impairments |  | (46) | (2)
Realized gains (losses) on securities |  | (551) | 184
Change in unrealized |  | (1,071) | 483
Fixed maturities |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | 29 | 3
Realized — impairments |  | (61) | (3)
Realized gains (losses) on securities |  | (32) | 0
Change in unrealized |  | (1,887) | 853
Equity securities |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | (535) | 182
Realized — impairments |  | 0 | 0
Realized gains (losses) on securities |  | (535) | 182
Change in unrealized |  | 0 | 0
Mortgage loans and other investments |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | 4 | 0
Realized — impairments |  | 0 | 0
Realized gains (losses) on securities |  | 4 | 0
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] | (3) | 1
Realized — impairments | [1] | 15 | 1
Realized gains (losses) on securities | [1] | 12 | 2
Change in unrealized | [1] | 816 | (370)
Tax effects |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments |  | 106 | (39)
Realized — impairments |  | 10 | 0
Realized gains (losses) on securities |  | 116 | (39)
Change in unrealized |  | $ 225 | $ (102)
[1] | Primarily adjustments to deferred policy acquisition costs and reserves related to the annuity business.

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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 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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