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Investments (Net realized investment gains (losses)) (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Fixed maturity securities: |  |  |  |
Gross gains | $ 5 | $ 13 | $ 18 | $ 27
Gross losses | (53) | (25) | (75) | (71)
Net investment gains (losses) on fixed maturity securities | (48) | (12) | (57) | (44)
Equity securities | 6 | 1 | 6 | 12
Short-term investments and other | 1 | 1 | 1 | 0
Net investment gains (losses) | (46) | (10) | (55) | (32)
Net Investment Income [Line Items] |  |  |  |
Gross gains | 5 | 13 | 18 | 27
Debt Securities, Available-for-sale, Realized Loss | 53 | 25 | 75 | 71
Debt Securities, Available-for-sale, Realized Gain (Loss) | (48) | (12) | (57) | (44)
Equity securities | 6 | 1 | 6 | 12
Mortgage loans | (5) | 0 | (5) | 0
Short-term investments and other | 1 | 1 | 1 | 0
Net investment losses | (46) | (10) | (55) | (32)
Non-redeemable preferred stock |  |  |  |
Net Investment Income [Line Items] |  |  |  |
Net investment income (loss) recognized due to the change in fair value of common stock held as of June 30, 2025 and 2024 | $ 6 | $ 1 | $ 4 | $ 12

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- Definition Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-9 + Details
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