Insurance Liabilities - Net Loss Reserve Discount Benefit (Charge) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Net Loss Reserve Discount Benefit (Charge) [Line Items] | |||
| Current accident year | $ 120 | $ 128 | $ 112 |
| Accretion and other adjustments to prior year discount | (168) | (303) | (264) |
| Net reserve discount benefit (charge) | (48) | (226) | (195) |
| Change in discount on loss reserves ceded under retroactive reinsurance | 45 | 168 | 150 |
| Net change in total reserve discount | (3) | (58) | (45) |
| North America Commercial Insurance | |||
| Net Loss Reserve Discount Benefit (Charge) [Line Items] | |||
| Effect of interest rate changes | 0 | (51) | (43) |
| United Kingdom | |||
| Net Loss Reserve Discount Benefit (Charge) [Line Items] | |||
| Net change in total reserve discount | $ (18) | $ (12) | $ 61 |