Future Contract Benefits - Summary of Discounted and Undiscounted Expected Future Gross Premiums and Expected Future Benefit Payments (Details) - USD ($) $ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Payout Annuities | ||
| Undiscounted | ||
| Expected future gross premiums | $ 0 | $ 0 |
| Expected future benefit payments | 3,243 | 3,408 |
| Discounted | ||
| Expected future gross premiums | 0 | 0 |
| Expected future benefit payments | 1,990 | 2,033 |
| Traditional Life | ||
| Undiscounted | ||
| Expected future gross premiums | 13,004 | 13,807 |
| Expected future benefit payments | 12,885 | 14,129 |
| Discounted | ||
| Expected future gross premiums | 8,973 | 9,447 |
| Expected future benefit payments | $ 8,922 | $ 9,654 |