INVESTMENT SECURITIES (Schedule of Investment Securities, Taxable and Nontaxable) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Net Investment Income [Line Items] | ||||
| Available-for-sale | $ 68 | $ 72 | $ 135 | $ 144 |
| Held-to-maturity | 46 | 51 | 94 | 104 |
| Interest on securities | 114 | 123 | 229 | 248 |
| Taxable | ||||
| Net Investment Income [Line Items] | ||||
| Available-for-sale | 62 | 65 | 123 | 130 |
| Held-to-maturity | 45 | 50 | 92 | 102 |
| Interest on securities | 107 | 115 | 215 | 232 |
| Nontaxable | ||||
| Net Investment Income [Line Items] | ||||
| Available-for-sale | 6 | 7 | 12 | 14 |
| Held-to-maturity | 1 | 1 | 2 | 2 |
| Interest on securities | $ 7 | $ 8 | $ 14 | $ 16 |