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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Millions |  | 3 Months Ended
--- | --- | ---
Feb. 10, 2023 USD ($) branch | Mar. 31, 2024 segment
Asset Acquisition [Line Items] |  |
Number of reporting segments | segment |  | 1
California | Three Branches Purchase |  |
Asset Acquisition [Line Items] |  |
Number of branches purchased | branch | 3 |
Deposit liabilities assumed | $ 376 |
Acquired receivables | 21 |
Goodwill | 12 |
Intangible assets acquired | $ 11 |

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