OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES - Summary of Various Financial Instruments With Off-balance Sheet Risk Outstanding (Details) $ in Thousands	Jun. 30, 2018 USD ($)
Financial instruments with off-balance sheet risk
1 year or less	$ 335,277
More than 1 year but less than 3 years	191,258
3 years or more but less than 5 years	85,615
5 years or more	87,725
Total	699,875
Commitments to extend credit
Financial instruments with off-balance sheet risk
1 year or less	325,665
More than 1 year but less than 3 years	190,944
3 years or more but less than 5 years	85,515
5 years or more	87,085
Total	689,209
Standby and commercial letters of credit
Financial instruments with off-balance sheet risk
1 year or less	9,612
More than 1 year but less than 3 years	314
3 years or more but less than 5 years	100
5 years or more	640
Total	$ 10,666