COMMITMENTS AND CONTINGENCIES, INCLUDING FINANCIAL INSTRUMENTS WITH OFF-BALANCE-SHEET RISK (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
COMMITMENTS AND CONTINGENCIES, INCLUDING FINANCIAL INSTRUMENTS WITH OFF-BALANCE-SHEET RISK
Commitments to extend credit, variable	$ 737,355	$ 626,441
Commitments to extend credit, fixed	93,007	61,608
Total	830,362	688,049
Standby letters of credit	$ 26,485	$ 28,977