| LOANS HELD FOR INVESTMENT AND ALLOWANCE FOR CREDIT LOSSES (Tables) | 12 Months Ended | 
|---|---|
| Dec. 31, 2023 | |
| Loans Held for Investment and Allowance for Credit Losses [Abstract] | |
| Schedule of Composition of the Loan Portfolio | (Dollars in Thousands)  2023  2022  Commercial, Financial and Agricultural  $  225,190 $  247,362 Real Estate – Construction  196,091 234,519 Real Estate – Commercial Mortgage  825,456 782,557 Real Estate – Residential (1) 1,004,219 749,513 Real Estate – Home Equity  210,920 208,217 Consumer (2) 272,042 325,517 Loans Held for Investment, Net of Unearned Income  $  2,733,918 $  2,547,685 (1) Includes loans in process with outstanding balances 3.2 6.1 (2) 1 .0 million and $ 1.1 | 
| Schedule of Activity in the Allowance for Loan Losses by Portfolio Class | Commercial,  Real Estate  Financial, Real Estate  Commercial Real Estate  Real Estate  (Dollars in Thousands)  Agricultural  Construction  Mortgage  Residential  Home Equity  Consumer  Total  2023  Beginning Balance  $  1,506 $  2,654 $  4,815 $  10,741 $  1,864 $  3,488 $  25,068 210 (154) 1,035 4,141 (233) 4,596 9,595 (511) - (120) (79) (39) (8,543) (9,292) 277 2 52 253 226 3,760 4,570 (234) 2 (68) 174 187 (4,783) (4,722) Ending Balance  $  1,482 $  2,502 $  5,782 $  15,056 $  1,818 $  3,301 $  29,941 2022  Beginning Balance  $  2,191 $  3,302 $  5,810 $  4,129 $  2,296 $  3,878 $  21,606 316 (658) (746) 6,328 (422) 2,579 7,397 (1,308) - (355) - (193) (6,050) (7,906) 307 10 106 284 183 3,081 3,971 (1,001) 10 (249) 284 (10) (2,969) (3,935) Ending Balance  $  1,506 $  2,654 $  4,815 $  10,741 $  1,864 $  3,488 $  25,068 2021  Beginning Balance  $  2,204 $  2,479 $  7,029 $  5,440 $  3,111 $  3,553 $  23,816 (227) 813 (1,679) (1,956) (1,125) 1,332 (2,842) (239) - (405) (108) (103) (3,972) (4,827) 453 10 865 753 413 2,965 5,459 214 10 460 645 310 (1,007) 632 Ending Balance  $  2,191 $  3,302 $  5,810 $  4,129 $  2,296 $  3,878 $  21,606 | 
| Schedule of Aging of the Recorded Investment in Accruing Past Due Loans by Class of Loans | 30-59 60-89 90 + Total  Total  Nonaccrual  Total  (Dollars in Thousands)  DPD  DPD  DPD  Past Due  Current  Loans  Loans  2023  Commercial, Financial and Agricultural  $  311 $  105 $  - $  416 $  224,463 $  311 $  225,190 Real Estate – Construction  206 - - 206 195,563 322 196,091 Real Estate – Commercial Mortgage  794 - - 794 823,753 909 825,456 Real Estate – Residential  670 34 - 704 1,000,525 2,990 1,004,219 Real Estate – Home Equity  268 - - 268 209,653 999 210,920 Consumer  3,693 774 - 4,467 266,864 711 272,042 Total  $  5,942 $  913 $  - $  6,855 $  2,720,821 $  6,242 $  2,733,918 2022  Commercial, Financial and Agricultural  $  109 $  126 $  - $  235 $  247,086 $  41 $  247,362 Real Estate – Construction  359 - - 359 234,143 17 234,519 Real Estate – Commercial Mortgage  158 149 - 307 781,605 645 782,557 Real Estate – Residential  845 530 - 1,375 747,899 239 749,513 Real Estate – Home Equity  - 35 - 35 207,411 771 208,217 Consumer  3,666 1,852 - 5,518 319,415 584 325,517 Total  $  5,137 $  2,692 $  - $  7,829 $  2,537,559 $  2,297 $  2,547,685 | 
| Schedule of Recorded Investment in Nonaccrual Loans and Loans Past Due Over 90 Days and Still on Accrual by Class of Loans | 2023  2022  Nonaccrual  Nonaccrual  90 + Days  Nonaccrual  Nonaccrual  90 + Days  With No  With  Still  With No  With  Still  (Dollars in Thousands)  ACL  ACL  Accruing  ACL  ACL  Accruing  Commercial, Financial and Agricultural  $  - $  311 $  - $  - $  41 $  - Real Estate – Construction  - 322 - - 17 - Real Estate – Commercial Mortgage  781 128 - 389 256 - Real Estate – Residential  1,705 1,285 - - 239 - Real Estate – Home Equity  - 999 - - 771 - Consumer  - 711 - - 584 - Total $  2,486 $  3,756 $  - $  389 $  1,908 $  - | 
| Amortized Cost Basis of Collateral-Dependent Loans | 2023  2022  Real Estate  Non Real Estate  Real Estate  Non Real Estate  (Dollars in Thousands)  Secured  Secured  Secured  Secured  Commercial, Financial and Agricultural  $  - $  30 $  - $  - Real Estate – Construction  275 - - - Real Estate – Commercial Mortgage  1,296 - 389 - Real Estate – Residential  1,706 - 160 - Real Estate – Home Equity  - - 130 - Consumer  - - 21 - Total  $  3,277 $  30 $  700 $  - | 
| Summary of Gross Loans Held for Investment by Years of Origination | Term Loans by Origination Year  Revolving  (Dollars in Thousands)  2023  2022  2021  2020  2019  Prior  Loans  Total  Commercial, Financial,  Agricultural:  Pass  $  57,320 $  66,671 $  28,933 $  10,610 $  7,758 $  7,502 $  44,350 $  223,144 Special Mention  168 608 356 10 9 - 76 1,227 Substandard  164 177 98 77 20 122 161 819 Total  $  57,652 $  67,456 $  29,387 $  10,697 $  7,787 $  7,624 $  44,587 $  225,190 Current-Period Gross  Writeoffs  $  6 $  252 $  65 $  31 $  41 $  19 $  97 $  511 Real Estate -  Construction:  Pass  $  101,684 $  68,265 $  18,181 $  - $  188 $  - $  4,617 $  192,935 Special Mention  631 500 539 212 - - - 1,882 Substandard  - 47 576 651 - - - 1,274 Total  $  102,315 $  68,812 $  19,296 $  863 $  188 $  - $  4,617 $  196,091 Current-Period Gross  Writeoffs  $  - $  - $  - $  - $  - $  - $  - $  - Real Estate - Commercial  Mortgage:  Pass  $  117,840 $  275,079 $  135,663 $  101,210 $  43,878 $  109,878 $  18,367 $  801,915 Special Mention  3,266 5,684 - 229 1,358 573 - 11,110 Substandard  - 1,226 6,695 1,637 605 1,574 694 12,431 Total  $  121,106 $  281,989 $  142,358 $  103,076 $  45,841 $  112,025 $  19,061 $  825,456 Current-Period Gross  Writeoffs  $  - $  - $  - $  - $  - $  120 $  - $  120 Real Estate - Residential:  Pass  $  372,394 $  400,437 $  83,108 $  35,879 $  24,848 $  68,685 $  8,252 $  993,603 Special Mention  268 89 83 502 - 313 - 1,255 Substandard  570 1,110 1,906 1,626 1,007 3,142 - 9,361 Total $  373,232 $  401,636 $  85,097 $  38,007 $  25,855 $  72,140 $  8,252 $  1,004,219 Current-Period Gross  Writeoffs  $  - $  - $  79 $  - $  - $  - $  - $  79 Real Estate - Home  Equity:  Performing  $  890 $  48 $  127 $  11 $  386 $  950 $  207,509 $  209,921 Nonperforming  - - - - - - 999 999 Total $  890 48 127 11 386 950 208,508 210,920 Current-Period Gross  Writeoffs  $  - $  - $  - $  - $  - $  - $  39 $  39 Consumer:  Performing  $  68,496 $  90,031 $  70,882 $  21,314 $  10,210 $  4,258 $  5,431 $  270,622 Nonperforming  293 355 58 4 - - 710 1,420 Total $  68,789 $  90,386 $  70,940 $  21,318 $  10,210 $  4,258 $  6,141 $  272,042 Current-Period Gross  Writeoffs  $  3,137 $  3,224 $  1,362 $  329 $  230 $  99 $  162 $  8,543 |