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LOAN PERFORMANCE - Aging analysis of past due loans, by loan class (Details) - USD ($)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Aging analysis
Total gross loans	$ 3,135,891,000		$ 2,876,427,000
Interest income that would have been earned under the original terms of the nonaccrual loans	809,000	$ 568,000
Total Current Loans
Aging analysis
Loans	3,113,738,000		2,875,291,000
30 to 59 days past due
Aging analysis
Loans	11,099,000		905,000
60 to 89 days past due
Aging analysis
Loans	9,172,000		34,000
90 days or greater past due
Aging analysis
Loans	1,882,000		197,000
Total Past Due
Aging analysis
Loans	22,153,000		1,136,000
Commercial and industrial
Aging analysis
Total gross loans	568,071,000		634,384,000
Commercial and industrial \| Total Current Loans
Aging analysis
Loans	560,000,000		634,370,000
Commercial and industrial \| 30 to 59 days past due
Aging analysis
Loans	4,374,000		14,000
Commercial and industrial \| 60 to 89 days past due
Aging analysis
Loans	3,416,000
Commercial and industrial \| 90 days or greater past due
Aging analysis
Loans	281,000
Commercial and industrial \| Total Past Due
Aging analysis
Loans	8,071,000		14,000
Commercial real estate
Aging analysis
Total gross loans	1,242,118,000		1,091,969,000
Commercial real estate \| Total Current Loans
Aging analysis
Loans	1,232,311,000		1,091,264,000
Commercial real estate \| 30 to 59 days past due
Aging analysis
Loans	5,360,000		650,000
Commercial real estate \| 60 to 89 days past due
Aging analysis
Loans	4,447,000
Commercial real estate \| 90 days or greater past due
Aging analysis
Loans			55,000
Commercial real estate \| Total Past Due
Aging analysis
Loans	9,807,000		705,000
Construction and development
Aging analysis
Total gross loans	507,570,000		460,719,000
Construction and development \| Total Current Loans
Aging analysis
Loans	506,220,000		460,577,000
Construction and development \| 30 to 59 days past due
Aging analysis
Loans	1,350,000
Construction and development \| 90 days or greater past due
Aging analysis
Loans			142,000
Construction and development \| Total Past Due
Aging analysis
Loans	1,350,000		142,000
1-4 family residential
Aging analysis
Total gross loans	288,456,000		277,273,000
1-4 family residential \| Total Current Loans
Aging analysis
Loans	285,546,000		277,089,000
1-4 family residential \| 30 to 59 days past due
Aging analysis
Loans			150,000
1-4 family residential \| 60 to 89 days past due
Aging analysis
Loans	1,309,000		34,000
1-4 family residential \| 90 days or greater past due
Aging analysis
Loans	1,601,000
1-4 family residential \| Total Past Due
Aging analysis
Loans	2,910,000		184,000
Multifamily residential
Aging analysis
Total gross loans	370,391,000		286,396,000
Multifamily residential \| Total Current Loans
Aging analysis
Loans	370,391,000		286,396,000
Consumer
Aging analysis
Total gross loans	24,509,000		28,090,000
Consumer \| Total Current Loans
Aging analysis
Loans	24,509,000		28,040,000
Consumer \| 30 to 59 days past due
Aging analysis
Loans			50,000
Consumer \| Total Past Due
Aging analysis
Loans			50,000
Agriculture
Aging analysis
Total gross loans	11,185,000		7,941,000
Agriculture \| Total Current Loans
Aging analysis
Loans	11,170,000		7,941,000
Agriculture \| 30 to 59 days past due
Aging analysis
Loans	15,000
Agriculture \| Total Past Due
Aging analysis
Loans	15,000
Other
Aging analysis
Total gross loans	123,591,000		89,655,000
Other:
Aging analysis
Total gross loans	123,591,000		89,655,000
Other: \| Total Current Loans
Aging analysis
Loans	$ 123,591,000		89,614,000
Other: \| 30 to 59 days past due
Aging analysis
Loans			41,000
Other: \| Total Past Due
Aging analysis
Loans			$ 41,000