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SECURITIES (Schedule of Carrying Value, Gross Unrealized Gains and Losses and Estimated Fair Value of Securities) (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Schedule of Held-to-maturity Securities [Line Items] |  |
Total HTM Securities | $ 543,575 | $ 544,851
Gross Unrealized Gains | 62,881 | 74,982
Gross Unrealized Losses | (97) | (68)
Held-to-maturity Securities, Fair Value | 606,359 | 619,765
U.S. government and agency securities |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Total HTM Securities | 2,676 | 2,751
Gross Unrealized Gains | 0 | 0
Gross Unrealized Losses | (31) | (18)
Held-to-maturity Securities, Fair Value | 2,645 | 2,733
Obligations of states and political subdivisions |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Total HTM Securities | 535,634 | 536,767
Gross Unrealized Gains | 62,880 | 74,978
Gross Unrealized Losses | 0 | 0
Held-to-maturity Securities, Fair Value | 598,514 | 611,745
Commercial |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Total HTM Securities | 5,265 | 5,333
Gross Unrealized Gains | 1 | 4
Gross Unrealized Losses | (66) | (50)
Held-to-maturity Securities, Fair Value | 5,200 | 5,287
Agency | Commercial |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Total HTM Securities | 5,265 | 5,333
Gross Unrealized Gains | 1 | 4
Gross Unrealized Losses | (66) | (50)
Held-to-maturity Securities, Fair Value | 5,200 | 5,287
Non-agency | Commercial |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Total HTM Securities | 0 | 0
Gross Unrealized Gains | 0 | 0
Gross Unrealized Losses | 0 | 0
Held-to-maturity Securities, Fair Value | $ 0 | $ 0

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