FAIR VALUE - Schedule of Carrying Amounts and Estimated Fair Value of Assets And Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financial assets:
Marketable securities held to maturity	$ 166,441	$ 176,790
Carrying Amount
Financial assets:
Cash, due from banks, federal funds sold and interest-bearing deposits	98,980	91,428
Marketable securities held to maturity	167,239	174,684
Loans, net	1,580,441	1,347,779
Accrued interest receivable	8,667	8,174
Nonmarketable equity securities	12,380	9,453
Cash surrender value of life insurance	25,590	19,117
Financial liabilities:
Deposits	1,848,425	1,676,320
Securities sold under repurchase agreements	12,588	12,879
Accrued interest payable	1,321	922
Federal Home Loan Bank advances	120,644	45,153
Subordinated debentures	13,810	13,810
Fair Value
Financial assets:
Cash, due from banks, federal funds sold and interest-bearing deposits	98,980	91,428
Marketable securities held to maturity	166,441	176,790
Loans, net	1,577,693	1,346,361
Accrued interest receivable	8,667	8,174
Nonmarketable equity securities	12,380	9,453
Cash surrender value of life insurance	25,590	19,117
Financial liabilities:
Deposits	1,847,160	1,676,445
Securities sold under repurchase agreements	12,588	12,879
Accrued interest payable	1,321	922
Federal Home Loan Bank advances	119,476	44,722
Subordinated debentures	11,604	11,495
Fair Value | Level 1 Inputs
Financial assets:
Cash, due from banks, federal funds sold and interest-bearing deposits	98,980	91,428
Marketable securities held to maturity	0	0
Loans, net	0	0
Accrued interest receivable	0	0
Nonmarketable equity securities	0	0
Cash surrender value of life insurance	0	0
Financial liabilities:
Deposits	1,478,570	1,378,467
Securities sold under repurchase agreements	0	0
Accrued interest payable	0	0
Federal Home Loan Bank advances	0	0
Subordinated debentures	0	0
Fair Value | Level 2 Inputs
Financial assets:
Cash, due from banks, federal funds sold and interest-bearing deposits	0	0
Marketable securities held to maturity	166,441	176,790
Loans, net	0	0
Accrued interest receivable	8,667	8,174
Nonmarketable equity securities	12,380	9,453
Cash surrender value of life insurance	25,590	19,117
Financial liabilities:
Deposits	368,590	297,978
Securities sold under repurchase agreements	12,588	12,879
Accrued interest payable	1,321	922
Federal Home Loan Bank advances	119,476	44,722
Subordinated debentures	11,604	11,495
Fair Value | Level 3 Inputs
Financial assets:
Cash, due from banks, federal funds sold and interest-bearing deposits	0	0
Marketable securities held to maturity	0	0
Loans, net	1,577,693	1,346,361
Accrued interest receivable	0	0
Nonmarketable equity securities	0	0
Cash surrender value of life insurance	0	0
Financial liabilities:
Deposits	0	0
Securities sold under repurchase agreements	0	0
Accrued interest payable	0	0
Federal Home Loan Bank advances	0	0
Subordinated debentures	$ 0	$ 0