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BORROWING ARRANGEMENTS - Narrative (Details) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2024 USD ($) oustanding_letters_of_credit credit_line | Dec. 31, 2023 USD ($)
Line of Credit Facility [Line Items] |  |
Number of credit lines maintained by the Company | credit_line | 3 |
Federal funds purchased | $ 0 | $ 0
FHLB borrowings, unused funds | 1,720,000,000 |
Securities sold under agreements to repurchase | $ 76,400,000 | 92,100,000
Maturity of repurchase agreements, less than | 1 year |
Asset Pledged As Collateral, Excess Amount |  |
Line of Credit Facility [Line Items] |  |
Debt Securities | $ 431,700,000 | 213,100,000
Federal Reserve Discount Window [Member] |  |
Line of Credit Facility [Line Items] |  |
Other borrowings | 0 | 300,000,000.0
Federal Reserve Bank Term Funding Program |  |
Line of Credit Facility [Line Items] |  |
Other borrowings | 0 | $ 117,700,000
Frost Bank |  |
Line of Credit Facility [Line Items] |  |
Line of credit, maximum borrowing capacity | 40,000,000.0 |
Line of credit facility, capacity available for issuance of letters of credit | $ 5,000,000.0 |
Number of outstanding letters of credit | oustanding_letters_of_credit | 1 |
Letters of Credit Outstanding, Amount | $ 155,000 |
TIB - The Independent Bankers Bank |  |
Line of Credit Facility [Line Items] |  |
Line of credit, maximum borrowing capacity | $ 15,000,000.0 |
FHLB |  |
Line of Credit Facility [Line Items] |  |
Number of outstanding letters of credit | oustanding_letters_of_credit | 1 |
Letters of Credit Outstanding, Amount | $ 6,100,000 |
Amegy Bank |  |
Line of Credit Facility [Line Items] |  |
Line of credit, maximum borrowing capacity | $ 25,000,000.0 |
Minimum |  |
Line of Credit Facility [Line Items] |  |
FHLB borrowings, interest rate at period end | 0.27% |
Maturity range of FHLB borrowings | 2 days |
Maximum |  |
Line of Credit Facility [Line Items] |  |
FHLB borrowings, interest rate at period end | 4.80% |
Maturity range of FHLB borrowings | 3 years 9 months 18 days |

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