DERIVATIVES - Schedule of Carrying Amount and Fair Value Hedge Adjustment of Hedged Assets (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Debt securities AFS (Note 2) | ||
| Derivative [Line Items] | ||
| Carrying Amount of Hedged Item | $ 1,155 | $ 1,473 |
| Amount of Fair Value Hedge Adjustment Included in the Carrying Amount | 95 | 27 |
| Borrowings (Note 7) | ||
| Derivative [Line Items] | ||
| Carrying Amount of Hedged Item | 2,392 | 0 |
| Amount of Fair Value Hedge Adjustment Included in the Carrying Amount | $ (99) | $ 0 |