INVESTMENT SECURITIES (Schedule of Investment Securities, Taxable and Nontaxable) (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Net Investment Income [Line Items] | ||
| Available-for-sale | $ 67 | $ 72 |
| Held-to-maturity | 48 | 53 |
| Interest on securities | 115 | 125 |
| Taxable | ||
| Net Investment Income [Line Items] | ||
| Available-for-sale | 61 | 65 |
| Held-to-maturity | 47 | 52 |
| Interest on securities | 108 | 117 |
| Nontaxable | ||
| Net Investment Income [Line Items] | ||
| Available-for-sale | 6 | 7 |
| Held-to-maturity | 1 | 1 |
| Interest on securities | $ 7 | $ 8 |