Investments - Hybrid Securities (Detail) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
Jun. 30, 2025 |
|---|---|---|---|
| Hybrid Instruments [Line Items] | |||
| Hybrid securities | $ 1,520 | $ 1,525 | $ 1,346 |
| Corporate and other debt | |||
| Hybrid Instruments [Line Items] | |||
| Hybrid securities | 693 | 733 | 731 |
| Residential mortgage-backed | |||
| Hybrid Instruments [Line Items] | |||
| Hybrid securities | $ 827 | $ 792 | $ 615 |