LOANS AND ALLOWANCE FOR CREDIT LOSSES - Past due (Details) - USD ($)	Jun. 30, 2025	Dec. 31, 2024	Jun. 30, 2024
Current - 29 Days Past Due	$ 949,240,000	$ 936,997,000
Total	958,935,000	946,826,000	$ 921,124,000
90 Days or Greater Past Due and Still Accruing Interest	621,000	756,000
Financial Asset, 30 to 59 Days Past Due
Total	3,507,000	4,636,000
Financing Receivables, 60 to 89 Days Past Due
Total	1,349,000	223,000
Financing Receivables, Equal to Greater than 90 Days Past Due
Total	4,839,000	4,970,000
Financial Asset, Past Due
Total	9,695,000	9,829,000
Real Estate
Current - 29 Days Past Due	855,206,000	841,218,000
Total	864,608,000	850,656,000	823,344,000
90 Days or Greater Past Due and Still Accruing Interest	621,000	756,000
Real Estate \| Financial Asset, 30 to 59 Days Past Due
Total	3,372,000	4,247,000
Real Estate \| Financing Receivables, 60 to 89 Days Past Due
Total	1,219,000	221,000
Real Estate \| Financing Receivables, Equal to Greater than 90 Days Past Due
Total	4,811,000	4,970,000
Real Estate \| Financial Asset, Past Due
Total	9,402,000	9,438,000
Agricultural
Current - 29 Days Past Due	1,108,000	936,000
Total	1,108,000	936,000	987,000
Commercial and Industrial
Current - 29 Days Past Due	64,626,000	66,328,000
Total	64,908,000	66,706,000	64,543,000
Commercial and Industrial \| Financial Asset, 30 to 59 Days Past Due
Total	124,000	378,000
Commercial and Industrial \| Financing Receivables, 60 to 89 Days Past Due
Total	130,000
Commercial and Industrial \| Financing Receivables, Equal to Greater than 90 Days Past Due
Total	28,000
Commercial and Industrial \| Financial Asset, Past Due
Total	282,000	378,000
Consumer
Current - 29 Days Past Due	6,284,000	6,377,000
Total	6,295,000	6,390,000	6,181,000
Consumer \| Financial Asset, 30 to 59 Days Past Due
Total	11,000	11,000
Consumer \| Financing Receivables, 60 to 89 Days Past Due
Total		2,000
Consumer \| Financial Asset, Past Due
Total	11,000	13,000
State and Political Subdivisions
Current - 29 Days Past Due	22,016,000	22,138,000
Total	$ 22,016,000	$ 22,138,000	$ 26,069,000