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INVESTMENT SECURITIES (Summary of Investment Securities) (Details) - USD ($) $ in Millions | Jun. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Amortized cost |  |
Available-for-sale | $ 10,406 | $ 10,601
Held-to-maturity | 9,272 | 9,669
Total investment securities | 19,678 | 20,270
Gross unrealized gains |  |
Available-for-sale | 12 | 1
Held-to-maturity | 49 | 2
Total investment securities | 61 | 3
Gross unrealized losses |  |
Available-for-sale | 1,302 | 1,507
Held-to-maturity | 92 | 289
Estimated fair value |  |
Available-for-sale | 9,116 | 9,095
Held-to-maturity, Estimated fair value | 9,229 | 9,382
Total investment securities | 18,345 | 18,477
Total investment securities | 1,394 | 1,796
U.S. Treasury securities |  |
Amortized cost |  |
Available-for-sale | 1,201 | 781
Gross unrealized gains |  |
Available-for-sale | 10 | 0
Gross unrealized losses |  |
Available-for-sale | 110 | 119
Estimated fair value |  |
Available-for-sale | 1,101 | 662
Agency securities |  |
Amortized cost |  |
Available-for-sale | 376 | 441
Held-to-maturity | 143 | 148
Gross unrealized gains |  |
Available-for-sale | 0 | 0
Held-to-maturity | 0 | 0
Gross unrealized losses |  |
Available-for-sale | 20 | 26
Held-to-maturity | 5 | 8
Estimated fair value |  |
Available-for-sale | 356 | 415
Held-to-maturity, Estimated fair value | 138 | 140
Agency guaranteed mortgage-backed securities |  |
Amortized cost |  |
Available-for-sale | 7,302 | 7,713
Held-to-maturity | 8,843 | 9,202
Gross unrealized gains |  |
Available-for-sale | 2 | 1
Held-to-maturity | 49 | 2
Gross unrealized losses |  |
Available-for-sale | 1,090 | 1,263
Held-to-maturity | 73 | 263
Estimated fair value |  |
Available-for-sale | 6,214 | 6,451
Held-to-maturity, Estimated fair value | 8,819 | 8,941
Small Business Administration loan-backed securities |  |
Amortized cost |  |
Available-for-sale | 400 | 455
Gross unrealized gains |  |
Available-for-sale | 0 | 0
Gross unrealized losses |  |
Available-for-sale | 16 | 21
Estimated fair value |  |
Available-for-sale | 384 | 434
Municipal securities |  |
Amortized cost |  |
Available-for-sale | 1,102 | 1,186
Held-to-maturity | 286 | 319
Gross unrealized gains |  |
Available-for-sale | 0 | 0
Held-to-maturity | 0 | 0
Gross unrealized losses |  |
Available-for-sale | 66 | 78
Held-to-maturity | 14 | 18
Estimated fair value |  |
Available-for-sale | 1,036 | 1,108
Held-to-maturity, Estimated fair value | 272 | 301
Other debt securities |  |
Amortized cost |  |
Available-for-sale | 25 | 25
Gross unrealized gains |  |
Available-for-sale | 0 | 0
Gross unrealized losses |  |
Available-for-sale | 0 | 0
Estimated fair value |  |
Available-for-sale | 25 | 25
Available-for-sale, Unrealized Gains, Other |  |
Gross unrealized gains |  |
Available-for-sale | $ 1 | $ 1

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