LOANS (Narrative) (Details)	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2020 USD ($) numberOfLoanCategories numberOfLoans	Jun. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) numberOfTDRLoans loan numberOfLoans numberOfLoanCategories	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) loan numberOfTDRLoans numberOfLoans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan categories | numberOfLoanCategories	2				2
Number of TDR loans | numberOfTDRLoans					6		8
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	$ 1,600,000				$ 1,600,000		$ 1,900,000
Deferred loan fees and premiums include net deferred fees paid by customers	3,300,000				3,300,000		3,300,000
Offset by net deferred premiums paid to purchase loans	$ 4,900,000				$ 4,900,000		$ 5,200,000
Total number of loans | numberOfLoans	37				37		39
Loans receivable	$ 1,627,620,000				$ 1,627,620,000		$ 1,454,172,000
Service rights retained, percent of outstanding balance	0.25%				0.25%
Service rights retained, amount	$ 26,500,000				$ 26,500,000		32,900,000
Non- accrual delinquent loans	17,228,000				17,228,000		12,787,000
Reserve for delinquent non accrual loans	468,000				468,000		522,000
Non-accrual loans included in TDR's	20,148,000				20,148,000		17,857,000
Financing receivable post modification recorded investment	2,103,000				$ 2,103,000		$ 2,049,000
Loans added to troubled debt restructuring | numberOfLoans					1		1
Amount of loans added to TDR					$ 191,000		$ 25,000
Allowance for loan loss	$ 18,829,000				$ 18,829,000		$ 10,942,000
Loans and leases receivable, allowance percentage	1.26%				1.26%		0.75%
Unpaid Contractual Principal Balance	$ 23,623,000		$ 28,263,000		$ 23,623,000	$ 28,263,000	$ 28,235,000
Total Recorded Investment	23,388,000		28,036,000		23,388,000	28,036,000	27,986,000
PCI Loans, accretion interest	111,000		242,000
Reclassification from (to) nonaccretable difference	0	$ 24,000	0	$ 156,000	24,000	156,000
Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	1,610,000				1,610,000		1,879,000
Loans receivable	$ 1,496,532,000		1,415,417,000		$ 1,496,532,000	1,415,417,000	$ 1,454,172,000
Percentage status of loan in portfolio	100.00%				100.00%		100.00%
Allowance for loan loss	$ (18,829,000)				$ (18,829,000)		$ (10,942,000)
Loans and leases receivable, allowance percentage	1.26%				1.26%		0.75%
Adjustable Rate Residential First Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,500,000,000				$ 1,500,000,000
Financing Receivable Troubled Debt Restructuring
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in finance receivables					$ 54,000
TDR loan principal curtailment							$ 236,000
One Troubled Debt Restructuring Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of TDR loans | loan					3
Non-accrual loans included in TDR's	1,530,000				$ 1,530,000		$ 1,400,000
Financing receivable post modification recorded investment	1,300,000				$ 1,300,000
Seven Troubled Debt Restructuring Loans with Reserves
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of TDR loans | loan							3
Specific reserves for TDR loans							$ 87,000
Financing receivable post modification recorded investment							$ 88,000
Seven Trouble Debt Restructuring Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans removed from troubled debt restructuring | loan					3		7
Amount of loans removed from troubled debt restructuring					$ 49,000		$ 4,400,000
U.S. SBA PPP Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	(3,300,000)				(3,300,000)
Offset by net deferred premiums paid to purchase loans	661,000				661,000
Deferred loan fees and premiums included in deferred fees paid by SBA	$ 3,900,000				$ 3,900,000
Total number of loans | numberOfLoans	963				963
Loans receivable	$ 131,100,000				$ 131,100,000
Interest rate, stated percentage	1.00%				1.00%
Loans with minimum financing term, percent of total	98.44%				98.44%
Loans with minimum financing term	$ 129,000,000.0				$ 129,000,000.0
Trouble Debt Restructuring Loans Disposal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of loans removed from troubled debt restructuring					88,000
Federal Reserve PPPLF Program Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 85,900,000				$ 85,900,000
Nonaccrual Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio	1.24%				1.24%		1.23%
Increase (decrease) in finance receivables					$ 2,300,000
Non- accrual delinquent loans	$ 20,100,000				20,100,000		$ 17,900,000
Decrease in loan delinquency							(1,400,000)
Nonaccrual Loans With No Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non- accrual delinquent loans	2,900,000				$ 2,900,000		$ 5,100,000
Percentage of current loans on total non accrual loans					14.00%		28.00%
Non-accrual loans included in TDR's	18,000,000.0				$ 18,000,000.0		$ 11,700,000
Interest due to debt					692,000		318,000
Nonaccrual Loans With Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non- accrual delinquent loans	17,200,000				$ 17,200,000		$ 12,800,000
Percentage of delinquent loans on total non accrual loans					86.00%		72.00%
Non-accrual loans included in TDR's	2,100,000				$ 2,100,000		$ 6,100,000
Interest due to debt					179,000		302,000
Minimum | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Bank exposure, threshold limit for credit rating					$ 1,000,000
Minimum | U.S. SBA PPP Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt Instrument, Term					2 years
Maximum | U.S. SBA PPP Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt Instrument, Term					5 years
Unrated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	542,686,000				$ 542,686,000		350,699,000
Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,061,892,000				1,061,892,000		1,076,610,000
Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 20,602,000				$ 20,602,000		$ 26,863,000
Residential rentals | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period					3 years
Residential rentals | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period					20 years
Receivables Under CARES, Act. | Executed Modifications, COVID-19 Loan Modification Program, Executed Modifications | Payment Deferral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of TDR loans | numberOfLoans					250
Outstanding balance of deferred loans					$ 251,500,000
Percent of portfolio loans	16.80%				16.80%
Receivables Under CARES, Act. | Minimum | Executed Modifications, COVID-19 Loan Modification Program, Executed Modifications | Payment Deferral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan deferral, period					90 days
Receivables Under CARES, Act. | Maximum | Executed Modifications, COVID-19 Loan Modification Program, Executed Modifications | Payment Deferral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan deferral, period					180 days
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of TDR loans | numberOfTDRLoans					2		3
Total number of loans | numberOfLoans	21				21		16
Loans receivable	$ 1,021,987,000				$ 1,021,987,000		$ 964,777,000
Largest commercial real estate loan outstanding	20,900,000				20,900,000		21,100,000
Non- accrual delinquent loans	14,859,000				14,859,000		10,562,000
Non-accrual loans included in TDR's	17,006,000				17,006,000		12,249,000
Financing receivable post modification recorded investment	1,376,000				1,376,000		1,420,000
Unpaid Contractual Principal Balance	18,355,000		21,159,000		18,355,000	21,159,000	20,914,000
Total Recorded Investment	18,148,000		20,974,000		18,148,000	20,974,000	20,707,000
Commercial real estate | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,021,987,000		932,344,000		$ 1,021,987,000	932,344,000	$ 964,777,000
Percentage status of loan in portfolio	68.29%				68.29%		66.34%
Commercial real estate | Unrated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 171,449,000				$ 171,449,000		$ 102,695,000
Commercial real estate | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	831,763,000				831,763,000		840,403,000
Commercial real estate | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 17,734,000				$ 17,734,000		$ 21,679,000
Commercial real estate | Commercial Construction Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio	8.30%				8.30%		8.90%
Percent of appraised value or sales price					80.00%
Residential first mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of TDR loans | numberOfTDRLoans					2		1
Total number of loans | numberOfLoans	3				3		3
Loans receivable	$ 147,756,000				$ 147,756,000		$ 167,710,000
Increase (decrease) in finance receivables					21,900,000		41,000,000.0
Non- accrual delinquent loans	333,000				333,000
Non-accrual loans included in TDR's	524,000				524,000		830,000
Financing receivable post modification recorded investment	254,000				254,000		64,000
Unpaid Contractual Principal Balance	1,741,000		2,089,000		1,741,000	2,089,000	1,921,000
Total Recorded Investment	1,739,000		2,089,000		1,739,000	2,089,000	1,917,000
Residential first mortgages | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 147,756,000		163,727,000		$ 147,756,000	163,727,000	$ 167,710,000
Percentage status of loan in portfolio	9.87%				9.87%		11.53%
Residential first mortgages | Adjustable Rate Residential First Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 37,000,000.0				$ 37,000,000.0		$ 52,300,000
Percentage status of loan in portfolio	2.50%				2.50%		3.60%
Residential first mortgages | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period					10 years
Residential first mortgages | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period					30 years
Residential rentals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total number of loans | numberOfLoans	2				2		5
Loans receivable	$ 137,950,000				$ 137,950,000		$ 123,601,000
Largest residential first mortgage loans outstanding, amount	3,000,000.0				3,000,000.0
Largest residential rental mortgage loan outstanding, amount	$ 9,600,000				$ 9,600,000
Number of properties secured as collateral | numberOfLoans	120				120
Non-accrual loans included in TDR's	$ 280,000				$ 280,000		937,000
Unpaid Contractual Principal Balance	636,000		956,000		636,000	956,000	941,000
Total Recorded Investment	636,000		956,000		636,000	956,000	937,000
Residential rentals | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 137,950,000		121,170,000		$ 137,950,000	121,170,000	$ 123,601,000
Percentage status of loan in portfolio	9.22%				9.22%		8.50%
Residential rentals | 1-4 Family Units
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 103,500,000				$ 103,500,000		$ 97,100,000
Residential rentals | Apartment Buildings Rentals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	34,500,000				$ 34,500,000		26,500,000
Percent of appraised value or sales price					80.00%
Residential rentals | Adjustable Rate Residential Rentals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 117,100,000				$ 117,100,000		$ 102,200,000
Percentage status of loan in portfolio	7.80%				7.80%		7.00%
Residential rentals | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period					3 years
Residential rentals | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period					20 years
Residential rentals | Unrated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 48,014,000				$ 48,014,000		$ 38,139,000
Residential rentals | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	89,105,000				89,105,000		84,811,000
Residential rentals | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0				0		651,000
Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 36,061,000				$ 36,061,000		$ 34,133,000
Percentage status of loan in portfolio	2.40%				2.40%		2.40%
Largest construction and land development loan outstanding, amount	$ 9,700,000				$ 9,700,000		$ 5,300,000
Construction and land development | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 36,061,000		30,774,000		$ 36,061,000	30,774,000	$ 34,133,000
Percentage status of loan in portfolio	2.41%				2.41%		2.35%
Construction and land development | Unrated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,321,000				$ 2,321,000		$ 2,075,000
Construction and land development | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	33,740,000				33,740,000		32,058,000
Construction and land development | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable							0
Home equity and second mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 31,400,000				$ 31,400,000		$ 36,100,000
Percentage status of loan in portfolio	2.10%				2.10%		2.50%
Home equity and second mortgages | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 31,427,000				$ 31,427,000		$ 36,098,000
Percentage status of loan in portfolio	2.10%				2.10%		2.48%
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total number of loans | numberOfLoans	2				2		3
Loans receivable	$ 58,894,000				$ 58,894,000		$ 63,102,000
Percentage status of loan in portfolio	3.90%				3.90%		4.30%
Debt maturity period					5 years
Largest commercial loan outstanding, amount	$ 6,400,000				$ 6,400,000		$ 2,800,000
Non- accrual delinquent loans	1,807,000				1,807,000		1,807,000
Non-accrual loans included in TDR's	1,807,000				1,807,000		3,127,000
Unpaid Contractual Principal Balance	1,807,000		2,641,000		1,807,000	2,641,000	3,127,000
Total Recorded Investment	1,807,000		2,629,000		1,807,000	2,629,000	3,127,000
Commercial loans | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 58,894,000		69,179,000		$ 58,894,000	69,179,000	$ 63,102,000
Percentage status of loan in portfolio	3.94%				3.94%		4.34%
Commercial loans | Unrated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 13,558,000				$ 13,558,000		$ 16,754,000
Commercial loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	43,529,000				43,529,000		43,221,000
Commercial loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,807,000				1,807,000		3,127,000
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,081,000				1,081,000		1,104,000
Consumer loans | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,081,000		937,000		$ 1,081,000	937,000	$ 1,104,000
Percentage status of loan in portfolio	0.07%				0.07%		0.08%
Commercial equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of TDR loans | numberOfTDRLoans					2		4
Total number of loans | numberOfLoans	3				3		6
Loans receivable	$ 61,376,000				$ 61,376,000		$ 63,647,000
Percentage status of loan in portfolio	4.10%				4.10%		4.40%
Largest commercial equipment loans, amount	$ 2,500,000				$ 2,500,000		$ 2,100,000
Non- accrual delinquent loans							241,000
Non-accrual loans included in TDR's	52,000				52,000		266,000
Financing receivable post modification recorded investment	473,000				473,000		565,000
Unpaid Contractual Principal Balance	532,000		830,000		532,000	830,000	808,000
Total Recorded Investment	518,000		811,000		518,000	811,000	788,000
Commercial equipment | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 61,376,000		61,104,000		$ 61,376,000	61,104,000	$ 63,647,000
Percentage status of loan in portfolio	4.10%				4.10%		4.38%
Commercial equipment | Unrated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 25,938,000				$ 25,938,000		$ 26,045,000
Commercial equipment | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	35,290,000				35,290,000		37,399,000
Commercial equipment | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 42,000				$ 42,000		$ 203,000
Loan Delinquency
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio	1.21%				1.21%		0.92%
Decrease in loan delinquency							$ (4,700,000)
Non-accrual loans included in TDR's	$ 18,100,000				$ 18,100,000		13,300,000
Performing Financial Instruments | Residential first mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	147,423,000				147,423,000		167,710,000
Performing Financial Instruments | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,081,000				1,081,000		1,104,000
Nonperforming Financial Instruments | Residential first mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	333,000				333,000		0
Nonperforming Financial Instruments | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 0				$ 0		0
Purchased credit impaired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio	0.09%				0.09%
Unpaid Contractual Principal Balance	$ 2,400,000				$ 2,400,000
Total Recorded Investment	2,000,000.0				2,000,000.0		2,400,000
Purchased credit impaired | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,985,000		2,803,000		1,985,000	2,803,000	2,424,000
Purchased credit impaired | Commercial real estate | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,581,000		1,732,000		1,581,000	1,732,000	1,738,000
Purchased credit impaired | Residential first mortgages | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0		451,000		0	451,000	0
Purchased credit impaired | Residential rentals | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0		317,000		0	317,000	295,000
Purchased credit impaired | Construction and land development | Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0		$ 0		0	$ 0	0
County First Acquisition
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 63,988,000				$ 63,988,000		$ 77,078,000
Percentage status of loan in portfolio	3.93%				3.93%		5.30%
County First Acquisition | Purchased credit impaired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,986,000				$ 1,986,000		$ 2,424,000
Percentage status of loan in portfolio	0.12%				0.12%		0.17%
County First Acquisition | All Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 62,002,000				$ 62,002,000		$ 74,654,000
Percentage status of loan in portfolio	3.81%				3.81%		5.13%
County First Bank Acquisition | Purchased credit impaired
Accounts, Notes, Loans and Financing Receivable [Line Items]
New acquisition accounting for fair market value adjustment	$ 380,000				$ 380,000		$ 516,000
Net acquisition accounting fair market value adjustment, mark	16.06%				16.06%		17.55%
County First Bank Acquisition | All Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
New acquisition accounting for fair market value adjustment	$ 814,000				$ 814,000		$ 1,200,000
Net acquisition accounting fair market value adjustment, mark	1.30%				1.30%		1.55%