OTHER BORROWINGS, Schedule of Other Borrowings (Details) - USD ($) $ in Millions |
Mar. 31, 2026 |
Sep. 30, 2025 |
|---|---|---|
| Other Borrowings [Line Items] | ||
| Total FHLB advances | $ 700 | $ 700 |
| FHLB Advance Maturing June 2026 - September 2027 | ||
| Other Borrowings [Line Items] | ||
| Weighted-average interest rate | 3.91% | |
| Total FHLB advances | $ 400 | |
| FHLB Advance Maturing December 2027 - December 2028 | ||
| Other Borrowings [Line Items] | ||
| Weighted-average interest rate | 3.99% | |
| Total FHLB advances | $ 300 | |
| FHLB Advance Maturing December 2025 - December 2026 | ||
| Other Borrowings [Line Items] | ||
| Weighted-average interest rate | 4.44% | |
| Total FHLB advances | $ 500 | |
| FHLB Advance Maturing December 2028 | ||
| Other Borrowings [Line Items] | ||
| Weighted-average interest rate | 4.10% | |
| Total FHLB advances | $ 200 |