Claim and Claim Adjustment Expense Reserves (International - Net prior year claim and allocated claim adjustment expense reserve development) (Details) - International - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Liability for Claims and Claims Adjustment Expense [Line Items] | ||||
| Commercial | $ (3) | $ 6 | $ (3) | $ 6 |
| Specialty | 4 | (9) | 4 | (9) |
| Other | (1) | 0 | (1) | 0 |
| Total pretax (favorable) unfavorable development | $ 0 | $ (3) | $ 0 | $ (3) |