LOANS AND ALLOWANCE FOR CREDIT LOSSES - Impaired loans (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Modifications [Line Items]
Financing Receivable, Recorded Investment			$ 7,480,000
Unpaid principal balance	$ 862,183,000	$ 779,028,000	858,469,000
Related allowance	7,142,000	8,937,000	8,274,000	$ 8,680,000
Recorded Investment
Total	5,346,000		11,207,000
Unpaid Principal Balance
With an allowance recorded	7,368,000		14,174,000
Total	7,368,000		14,174,000
Average Recorded Investment
Total	5,354,000	13,560,000
Interest Income Recognized
Total	6,000	74,000
Real Estate
Financing Receivable, Modifications [Line Items]
Unpaid principal balance	767,060,000		764,880,000
Related allowance	6,735,000		7,483,000
Recorded Investment
With no related allowance recorded	4,376,000
Total	4,376,000
Unpaid Principal Balance
With no related allowance recorded	6,398,000
With an allowance recorded	6,398,000
Total	6,398,000
Average Recorded Investment
With no related allowance recorded	4,381,000
Total	4,381,000
Agricultural
Financing Receivable, Modifications [Line Items]
Unpaid principal balance	783,000		860,000
Related allowance	1,000		6,000
Recorded Investment
With no related allowance recorded	309,000
Total	309,000
Unpaid Principal Balance
With no related allowance recorded	309,000
With an allowance recorded	309,000
Total	309,000
Average Recorded Investment
With no related allowance recorded	309,000
Total	309,000
Interest Income Recognized
With no related allowance recorded	6,000
Total	6,000
Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Unpaid principal balance	58,280,000		56,077,000
Related allowance	265,000		504,000
Recorded Investment
With no related allowance recorded	661,000
Total	661,000
Unpaid Principal Balance
With no related allowance recorded	661,000
With an allowance recorded	661,000
Total	661,000
Average Recorded Investment
With no related allowance recorded	664,000
Total	$ 664,000
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Unpaid principal balance		81,831,000	86,999,000
Related allowance		665,000	704,000	681,000
Recorded Investment
With no related allowance recorded			973,000
Total			973,000
Unpaid Principal Balance
With no related allowance recorded			973,000
With an allowance recorded			973,000
Total			973,000
Average Recorded Investment
With no related allowance recorded		1,010,000
Total		1,010,000
Interest Income Recognized
With no related allowance recorded		2,000
Total		2,000
Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Unpaid principal balance		549,921,000	611,549,000
Related allowance		5,759,000	5,932,000	5,408,000
Recorded Investment
With no related allowance recorded			9,495,000
Total			9,495,000
Unpaid Principal Balance
With no related allowance recorded			12,430,000
With an allowance recorded			12,430,000
Total			12,430,000
Average Recorded Investment
With no related allowance recorded		11,699,000
Total		11,699,000
Interest Income Recognized
With no related allowance recorded		72,000
Total		72,000
Residential Real Estate
Financing Receivable, Modifications [Line Items]
Unpaid principal balance		141,990,000	154,506,000
Related allowance		1,538,000	1,557,000	$ 1,539,000
Recorded Investment
With no related allowance recorded			739,000
Total			739,000
Unpaid Principal Balance
With no related allowance recorded			771,000
With an allowance recorded			771,000
Total			$ 771,000
Average Recorded Investment
With no related allowance recorded		851,000
Total		$ 851,000