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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, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized gains (losses) on securities | $ (17) | $ 23 | $ 103 | $ (197)
Net of tax |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | (12) | 18 | 82 | (145)
Realized — impairments | 0 | 0 | 1 | (11)
Realized gains (losses) on securities | (12) | 18 | 83 | (156)
Change in unrealized | (27) | 47 | (46) | 31
Total pretax |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | (17) | 23 | 102 | (183)
Realized — impairments | 0 | 0 | 1 | (14)
Realized gains (losses) on securities | (17) | 23 | 103 | (197)
Change in unrealized | (35) | 59 | (59) | 39
Fixed maturities |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | (2) | 1 | (2) | 5
Realized — impairments | 0 | 0 | 1 | (14)
Realized gains (losses) on securities | (2) | 1 | (1) | (9)
Change in unrealized | (35) | 59 | (59) | 39
Equity securities |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | (15) | 22 | 104 | (189)
Realized — impairments | 0 | 0 | 0 | 0
Realized gains (losses) on securities | (15) | 22 | 104 | (189)
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 | 1
Realized — impairments | 0 | 0 | 0 | 0
Realized gains (losses) on securities | 0 | 0 | 0 | 1
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 | 5 | (5) | (20) | 38
Realized — impairments | 0 | 0 | 0 | 3
Realized gains (losses) on securities | 5 | (5) | (20) | 41
Change in unrealized | $ 8 | $ (12) | $ 13 | $ (8)

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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://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 8A -URI http://asc.fasb.org/extlink&oid=124260329&loc=SL6284422-111562 + Details
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