COMMITMENTS AND CONTINGENCIES, INCLUDING FINANCIAL INSTRUMENTS WITH OFF-BALANCE-SHEET RISK (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
COMMITMENTS AND CONTINGENCIES AND FINANCIAL INSTRUMENTS WITH OFF-BALANCE-SHEET RISK
Commitments to extend credit, variable	$ 626,441	$ 493,740
Commitments to extend credit, fixed	61,608	113,719
Total	688,049	607,459
Standby letters of credit	$ 28,977	$ 26,682