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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 | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized gains (losses) on securities | $ (36) | $ (116) | $ 110
Net of tax |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments | (20) | (90) | 86
Realized - impairments | (8) | (2) | 1
Realized gains (losses) on securities | (28) | (92) | 87
Change in unrealized | 210 | (633) | (88)
Total pretax |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments | (25) | (113) | 109
Realized - impairments | (11) | (3) | 1
Realized gains (losses) on securities | (36) | (116) | 110
Change in unrealized | 267 | (803) | (111)
Fixed maturities |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments | (35) | (27) | (1)
Realized - impairments | (10) | (3) | 1
Realized gains (losses) on securities | (45) | (30) | 0
Change in unrealized | 267 | (803) | (111)
Equity securities |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments | 10 | (96) | 110
Realized - impairments | 0 | 0 | 0
Realized gains (losses) on securities | 10 | (96) | 110
Change in unrealized | 0 | 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 | 10 | 0
Realized - impairments | (1) | 0 | 0
Realized gains (losses) on securities | (1) | 10 | 0
Change in unrealized | 0 | 0 | 0
Total tax effects |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |
Realized before impairments | 5 | 23 | (23)
Realized - impairments | 3 | 1 | 0
Realized gains (losses) on securities | 8 | 24 | (23)
Change in unrealized | $ (57) | $ 170 | $ 23

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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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