Future Policy Benefit Reserves - Narrative (Details) - USD ($) $ in Millions |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Dec. 31, 2025 |
|
| Insurance [Abstract] | |||
| Liability for future policy benefit, expected future gross premium, discounted, before reinsurance | $ 3,381 | $ 3,550 | |
| Liability for future policy benefit, weighted-average duration | 11 years | 11 years | |
| Liability future policy benefit, losses recognized in current period | $ 22 | $ 14 | |
| Liability future policy benefit, losses recognized in prior period | $ 8 | $ 6 | |