LOANS AND THE ALLOWANCE FOR LOAN LOSSES - Summary of unpaid principal balance of loans classified as TDRs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) loan	Jun. 30, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as TDRs		$ 11,590
Total Recorded Investment	$ 17,835	12,803
Allowance for loan associated with TDR	(940)	(940)
Net recorded investment	$ 16,895	10,650
Additional funds to loans classified as TDRs		400
Cash collateral received		1,500
Number of contracts modified | loan	2
Cash, Securities and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as TDRs		5,107
Total Recorded Investment	$ 11,252	5,107
1-4 Family Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Recorded Investment		1,213
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as TDRs		6,483
Total Recorded Investment	6,583	6,483
Allowance for loan associated with TDR	(940)	(940)
Investment accruing interest	5,400	5,400
Investment non-accruing interest	$ 1,000	$ 1,000