INVESTMENT SECURITIES (Schedule of Investment Securities, Taxable and Nontaxable) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Net Investment Income [Line Items] | ||||
| Available-for-sale | $ 70 | $ 73 | $ 205 | $ 217 |
| Held-to-maturity | 45 | 51 | 139 | 155 |
| Interest on securities | 115 | 124 | 344 | 372 |
| Taxable | ||||
| Net Investment Income [Line Items] | ||||
| Available-for-sale | 65 | 66 | 188 | 196 |
| Held-to-maturity | 44 | 49 | 136 | 151 |
| Interest on securities | 109 | 115 | 324 | 347 |
| Nontaxable | ||||
| Net Investment Income [Line Items] | ||||
| Available-for-sale | 5 | 7 | 17 | 21 |
| Held-to-maturity | 1 | 2 | 3 | 4 |
| Interest on securities | $ 6 | $ 9 | $ 20 | $ 25 |