Future Policy Benefits - Schedule of Revenue and Interest Expense in Respect of Future Policy Benefits (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | |
|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Dec. 31, 2025 |
|
| Disclosure In Tabular Form Of Revenue And Interest Expense In Respect Of Future Policy Benefits [Line Items] | |||
| Gross premiums | $ 768 | $ 774 | $ 3,141 |
| Interest accretion | 770 | 766 | 3,065 |
| Long-term care insurance | |||
| Disclosure In Tabular Form Of Revenue And Interest Expense In Respect Of Future Policy Benefits [Line Items] | |||
| Gross premiums | 623 | 619 | 2,544 |
| Interest accretion | 611 | 598 | 2,406 |
| Life insurance | |||
| Disclosure In Tabular Form Of Revenue And Interest Expense In Respect Of Future Policy Benefits [Line Items] | |||
| Gross premiums | 145 | 155 | 597 |
| Interest accretion | 8 | 12 | 42 |
| Fixed annuities | |||
| Disclosure In Tabular Form Of Revenue And Interest Expense In Respect Of Future Policy Benefits [Line Items] | |||
| Gross premiums | 0 | 0 | 0 |
| Interest accretion | $ 151 | $ 156 | $ 617 |