COLLATERALIZED AGREEMENTS AND FINANCINGS, Collateral (Details) - USD ($) $ in Millions |
Jun. 30, 2025 |
Sep. 30, 2024 |
|---|---|---|
| Collateral Received that Can be Resold or Repledged [Abstract] | ||
| Collateral we received that was available to be delivered or repledged | $ 4,093 | $ 3,800 |
| Collateral that we delivered or repledged | $ 1,581 | $ 1,653 |