Future Policy Benefits Reserves - Additional Information (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Insurance [Abstract] | ||
| Liability for future policy benefit, expected future gross premium, discounted, before reinsurance | $ 3,600 | $ 3,700 |
| Liability for future policy benefit, weighted-average duration (in years) | 11 years | 11 years |
| Liability for future policy benefit, adverse development, expense | $ 14 | $ 20 |
| Liability future policy benefit, losses recognized in prior period | $ 6 | $ 2 |