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SECURITIES (Amortized Cost of HTM Securities by Security Type and Credit Rating) (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
HTM Securities, Amortized Cost | $ 543,575 | $ 544,851
Moody's AAA/AA/A |  |
HTM Securities, Amortized Cost | 531,203 | 532,157
Moody's Not Rated - Agency |  |
HTM Securities, Amortized Cost | 7,941 | 8,084
Moody's Not Rated - Non-Agency |  |
HTM Securities, Amortized Cost | 4,431 | 4,610
U.S. government and agency securities |  |
HTM Securities, Amortized Cost | 2,676 | 2,751
U.S. government and agency securities | Moody's AAA/AA/A |  |
HTM Securities, Amortized Cost | 0 | 0
U.S. government and agency securities | Moody's Not Rated - Agency |  |
HTM Securities, Amortized Cost | 2,676 | 2,751
U.S. government and agency securities | Moody's Not Rated - Non-Agency |  |
HTM Securities, Amortized Cost | 0 | 0
Obligations of states and political subdivisions |  |
HTM Securities, Amortized Cost | 535,634 | 536,767
Obligations of states and political subdivisions | Moody's AAA/AA/A |  |
HTM Securities, Amortized Cost | 531,203 | 532,157
Obligations of states and political subdivisions | Moody's Not Rated - Agency |  |
HTM Securities, Amortized Cost | 0 | 0
Obligations of states and political subdivisions | Moody's Not Rated - Non-Agency |  |
HTM Securities, Amortized Cost | 4,431 | 4,610
Total mortgage-back securities |  |
HTM Securities, Amortized Cost | 5,265 | 5,333
Total mortgage-back securities | Moody's AAA/AA/A |  |
HTM Securities, Amortized Cost | 0 | 0
Total mortgage-back securities | Moody's Not Rated - Agency |  |
HTM Securities, Amortized Cost | 5,265 | 5,333
Total mortgage-back securities | Moody's Not Rated - Non-Agency |  |
HTM Securities, Amortized Cost | $ 0 | $ 0

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