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FAIR VALUE DISCLOSURES - Certain assets measured on a non recurring basis (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Loan Impairment Assessment
Recorded Investment		$ 3,426
Related Allowance		437
Total Recorded Investment		12,917
Risk rating	$ 2,895,210	2,613,805
Financing Receivable, Allowance for Credit Losses	39,678	25,280	$ 25,342	$ 23,693
Total loans	2,947,767	2,646,673
Non-recurring basis \| Level 3 Inputs
Loan Impairment Assessment
Recorded Investment	10,218	3,426
Related Allowance	2,871	437
Total Recorded Investment	7,347	2,989
Commercial and industrial
Loan Impairment Assessment
Recorded Investment		699
Related Allowance		416
Total Recorded Investment		999
Financing Receivable, Allowance for Credit Losses	12,108	7,671	7,792	7,719
Total loans	837,667	527,607
Commercial and industrial \| Non-recurring basis \| Level 3 Inputs
Loan Impairment Assessment
Recorded Investment	7,470	699
Related Allowance	2,403	416
Total Recorded Investment	5,067	283
Commercial real estate
Loan Impairment Assessment
Total Recorded Investment		1,404
Financing Receivable, Allowance for Credit Losses	12,424	7,975	7,371	6,730
Total loans	908,027	900,746
1-4 family residential
Loan Impairment Assessment
Recorded Investment		1,485
Related Allowance		15
Total Recorded Investment		3,651
Financing Receivable, Allowance for Credit Losses	3,173	2,257	2,236	2,281
Total loans	272,253	280,192
1-4 family residential \| Non-recurring basis \| Level 3 Inputs
Loan Impairment Assessment
Recorded Investment	1,507	1,485
Related Allowance		15
Total Recorded Investment	1,507	1,470
Consumer
Loan Impairment Assessment
Total Recorded Investment		210
Financing Receivable, Allowance for Credit Losses	529	388	458	387
Total loans	36,338	36,782
Agriculture
Loan Impairment Assessment
Financing Receivable, Allowance for Credit Losses	134	74	73	62
Total loans	7,795	9,812
Other
Loan Impairment Assessment
Recorded Investment		1,242
Related Allowance		6
Total Recorded Investment		6,653
Financing Receivable, Allowance for Credit Losses	1,380	770	655	$ 705
Total loans	77,535	86,513
Other \| Non-recurring basis \| Level 3 Inputs
Loan Impairment Assessment
Recorded Investment	1,241	1,242
Related Allowance	468	6
Total Recorded Investment	773	$ 1,236
Specific reserve
Loan Impairment Assessment
Financing Receivable, Allowance for Credit Losses	2,871		796
Specific reserve \| Commercial and industrial
Loan Impairment Assessment
Financing Receivable, Allowance for Credit Losses	2,403		699
Specific reserve \| Commercial real estate
Loan Impairment Assessment
Financing Receivable, Allowance for Credit Losses			29
Specific reserve \| 1-4 family residential
Loan Impairment Assessment
Financing Receivable, Allowance for Credit Losses			46
Specific reserve \| Consumer
Loan Impairment Assessment
Financing Receivable, Allowance for Credit Losses			$ 22
Specific reserve \| Other
Loan Impairment Assessment
Financing Receivable, Allowance for Credit Losses	$ 468