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FAIR VALUE - Carrying amounts and estimated fair values of other financial instruments (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Financial assets: |  |
Held-to-maturity securities | $ 1,131,615 | $ 1,121,816
Carrying Value |  |
Financial assets: |  |
Net loans | 9,813,409 | 9,637,929
Held-to-maturity securities | 1,217,472 | 1,172,174
Financial liabilities: |  |
Deposits | 13,352,022 | 12,928,121
Overnight borrowings | 0 | 53,000
Securities sold under agreement to repurchase, short-term | 287,241 | 304,595
Other Federal Home Loan Bank borrowings | 395,122 | 407,603
Fair Value |  |
Financial assets: |  |
Net loans | 9,366,599 | 9,293,902
Held-to-maturity securities | 1,131,615 | 1,121,816
Financial liabilities: |  |
Deposits | 13,326,950 | 12,907,605
Overnight borrowings | 0 | 53,000
Securities sold under agreement to repurchase, short-term | 287,241 | 304,595
Other Federal Home Loan Bank borrowings | $ 391,311 | $ 410,385

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