Investments - Equity securities reported at fair value (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
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| Debt and Equity Securities, FV-NI [Line Items] | ||
| Fair Value | $ 765 | $ 785 |
| Equity securities | ||
| Debt and Equity Securities, FV-NI [Line Items] | ||
| Actual Cost | 716 | 730 |
| Fair Value | 765 | 785 |
| Fair Value Over Cost | 49 | 55 |
| Common stocks | ||
| Debt and Equity Securities, FV-NI [Line Items] | ||
| Actual Cost | 342 | 332 |
| Fair Value | 380 | 365 |
| Fair Value Over Cost | 38 | 33 |
| Perpetual preferred stocks | ||
| Debt and Equity Securities, FV-NI [Line Items] | ||
| Actual Cost | 374 | 398 |
| Fair Value | 385 | 420 |
| Fair Value Over Cost | $ 11 | $ 22 |
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- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI) in excess of the cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value. No definition available.
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- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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