Investments (Supplemental Net Investment Gains (Losses)) (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Net Investment Income [Line Items] | ||
| Equity Securities, FV-NI, Unrealized Gain (Loss) | $ 16 | $ 13 |
| Realized gains (losses) on investments sold or disposed | (65) | (176) |
| Foreign Currency Transaction Gain (Loss), Realized | 5 | (27) |
| Debt and Equity Securities, Realized Gain (Loss) | (65) | (176) |
| Net investment Income | ||
| Net Investment Income [Line Items] | ||
| Debt and Equity Securities, Realized Gain (Loss) | 0 | 0 |
| Equity securities | ||
| Net Investment Income [Line Items] | ||
| Equity Securities, FV-NI, Unrealized Gain (Loss) | $ 10 | $ (8) |
| X | ||||||||||
- Definition Amount of realized gain (loss) on investment in debt and equity securities. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- 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
|
| X | ||||||||||
- Definition Amount, before tax, of realized gain (loss) from foreign currency transaction. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of realized gain (loss) on investment. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- 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
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|