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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 | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized gains (losses) on securities | $ (19) | $ (35) | $ (67) | $ (143)
Net of tax |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | (12) | (26) | (46) | (112)
Realized — impairments | (3) | (2) | (7) | (1)
Realized gains (losses) on securities | (15) | (28) | (53) | (113)
Change in unrealized | (57) | (228) | (24) | (690)
Total pretax |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | (15) | (33) | (58) | (142)
Realized — impairments | (4) | (2) | (9) | (1)
Realized gains (losses) on securities | (19) | (35) | (67) | (143)
Change in unrealized | (72) | (288) | (29) | (874)
Fixed maturities: |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | (7) | (6) | (35) | (20)
Realized — impairments | (4) | (2) | (9) | (1)
Realized gains (losses) on securities | (11) | (8) | (44) | (21)
Change in unrealized | (72) | (288) | (29) | (874)
Equity securities |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | (8) | (27) | (23) | (122)
Realized — impairments | 0 | 0 | 0 | 0
Realized gains (losses) on securities | (8) | (27) | (23) | (122)
Change in unrealized | 0 | 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 | 0 | 0 | 0
Realized — impairments | 0 | 0 | 0 | 0
Realized gains (losses) on securities | 0 | 0 | 0 | 0
Change in unrealized | 0 | 0 | 0 | 0
Tax effects |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | 3 | 7 | 12 | 30
Realized — impairments | 1 | 0 | 2 | 0
Realized gains (losses) on securities | 4 | 7 | 14 | 30
Change in unrealized | $ 15 | $ 60 | $ 5 | $ 184

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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 other-than-temporary impairment (OTTI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), recognized in earnings. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 8A -Publisher FASB -URI https://asc.fasb.org//1943274/2147481830/320-10-45-8A + Details
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