Investments (Details) - Investment Information, Equity Securities - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | |
|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Dec. 31, 2025 |
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| Investment disclosure details | |||
| Equity securities, cost | $ 428 | $ 457 | |
| Gross gains | 170 | 178 | |
| Gross losses | 7 | 17 | |
| Equity securities, at fair value | 591 | 618 | |
| Net recognized losses on equity securities still held | 5 | $ 22 | |
| Amounts classified as held for sale [Member] | |||
| Investment disclosure details | |||
| Equity securities, cost | 69 | ||
| Equity securities, at fair value | 104 | ||
| Common stock [Member] | |||
| Investment disclosure details | |||
| Equity securities, cost | 397 | 419 | |
| Gross gains | 168 | 177 | |
| Gross losses | 7 | 12 | |
| Equity securities, at fair value | 558 | 584 | |
| Non-redeemable preferred stock [Member] | |||
| Investment disclosure details | |||
| Equity securities, cost | 31 | 38 | |
| Gross gains | 2 | 1 | |
| Gross losses | 0 | 5 | |
| Equity securities, at fair value | $ 33 | $ 34 | |
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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 Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of unrealized loss on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). 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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