Investments (Invested Assets on Deposit, Held in Trust and Pledged as Collateral - Narrative) (Details) - USD ($) $ in Millions |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Statement [Line Items] | ||
| Funds Held under Reinsurance Agreements, Asset | $ 22,300 | $ 22,400 |
| Federal Home Loan Bank Stock | 700 | 700 |
| Assets Held-in-trust | 3,646 | 1,775 |
| Affiliated Entity | ||
| Statement [Line Items] | ||
| Assets Held-in-trust | 1,800 | 1,800 |
| Cash, cash equivalents and short-term investments (1) | ||
| Statement [Line Items] | ||
| Funds Held under Reinsurance Agreements, Asset | $ 1,000 | $ 1,200 |