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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 | 6 Months Ended
--- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized gains (losses) on securities | $ 43 | $ 108 | $ 120 | $ (220)
Net of tax |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | 34 | 85 | 94 | (163)
Realized — impairments | 0 | 0 | 1 | (11)
Realized gains (losses) on securities | 34 | 85 | 95 | (174)
Change in unrealized | 16 | 203 | (19) | (16)
Total pretax |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | 43 | 108 | 119 | (206)
Realized — impairments | 0 | 0 | 1 | (14)
Realized gains (losses) on securities | 43 | 108 | 120 | (220)
Change in unrealized | 20 | 257 | (24) | (20)
Fixed maturities |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | 1 | 1 | 0 | 4
Realized — impairments | 0 | 0 | 1 | (14)
Realized gains (losses) on securities | 1 | 1 | 1 | (10)
Change in unrealized | 20 | 257 | (24) | (20)
Equity securities |  |  |  |
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments |  |  |  |
Realized before impairments | 42 | 107 | 119 | (211)
Realized — impairments | 0 | 0 | 0 | 0
Realized gains (losses) on securities | 42 | 107 | 119 | (211)
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 | (9) | (23) | (25) | 43
Realized — impairments | 0 | 0 | 0 | 3
Realized gains (losses) on securities | (9) | (23) | (25) | 46
Change in unrealized | $ (4) | $ (54) | $ 5 | $ 4

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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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