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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, 2021 | Mar. 31, 2020
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |
Realized gains (losses) on securities | $ 77 | $ (328)
Net of tax |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |
Realized before impairments | 60 | (248)
Realized — impairments | 1 | (11)
Realized gains (losses) on securities | 61 | (259)
Change in unrealized | (35) | (219)
Total pretax |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |
Realized before impairments | 76 | (314)
Realized — impairments | 1 | (14)
Realized gains (losses) on securities | 77 | (328)
Change in unrealized | (44) | (277)
Fixed maturities |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |
Realized before impairments | (1) | 3
Realized — impairments | 1 | (14)
Realized gains (losses) on securities | 0 | (11)
Change in unrealized | (44) | (277)
Equity securities |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |
Realized before impairments | 77 | (318)
Realized — impairments | 0 | 0
Realized gains (losses) on securities | 77 | (318)
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 | 0 | 1
Realized — impairments | 0 | 0
Realized gains (losses) on securities | 0 | 1
Change in unrealized | 0 | 0
Tax effects |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |
Realized before impairments | (16) | 66
Realized — impairments | 0 | 3
Realized gains (losses) on securities | (16) | 69
Change in unrealized | $ 9 | $ 58

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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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