Commitments, Contingencies and Guarantees (Commitments to Fund Investments) (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Limited Partner [Member] | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability | $ 2,373 | $ 2,328 |
| Commercial Loan [Member] | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability | 296 | 192 |
| Bank Loans [Member] | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability | 2,595 | 2,796 |
| Equity Release Mortgages [Member] | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability | $ 114 | $ 128 |