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LOANS - Summary of Balances of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans
Total loans	$ 3,165,733	$ 2,980,252
Net deferred loan costs	5,825	5,255
Less: Allowance for loan losses	(24,060)	(20,655)	$ (18,489)	$ (16,968)
Net loans	3,147,498	2,964,852
Commercial loans
Loans
Total loans	1,632,540	1,373,351
Residential
Loans
Total loans	1,100,424	1,115,456
Less: Allowance for loan losses	(3,178)	(3,239)	(4,000)	(4,963)
Residential \| 1-4 family
Loans
Total loans	931,846	942,659
Residential \| Second mortgages and equity lines of credit
Loans
Total loans	154,523	158,138
Residential \| Residential Construction
Loans
Total loans	14,055	14,659
Commercial real estate
Loans
Total loans	1,172,351	934,420
Less: Allowance for loan losses	(12,875)	(10,059)	(7,835)	(7,150)
Commercial Construction
Loans
Total loans	153,907	161,660
Less: Allowance for loan losses	(2,526)	(2,707)	(1,810)	(924)
Commercial
Loans
Total loans	306,282	277,271
Less: Allowance for loan losses	(2,977)	(2,286)	(2,254)	(1,920)
Consumer loans
Loans
Total loans	432,769	491,445
Less: Allowance for loan losses	(1,010)	(1,154)	$ (1,000)	$ (780)
Consumer loans \| Auto
Loans
Total loans	421,513	478,863
Consumer loans \| Personal
Loans
Total loans	$ 11,256	$ 12,582