SUBSEQUENT EVENT (Details) - AltaPacific Bank [Member] - Subsequent Event [Member] $ / shares in Units, $ in Millions	Jul. 24, 2019 USD ($) $ / shares shares
Subsequent Event [Line Items]
Business Combination, Combined Assets	$ 12,200.0
Subsequent Event, Date	Jul. 24, 2019
Business Combination, Consideration Transferred, Equity Interest Issued And Issuable, Shares | shares	0.2712
Business Combination, Consideration Transfered, Per Share Value | $ / shares	$ 54.19
Business Combination, consideration transfered	$ 87.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	436.0
Loans receivable (contractual amount of $645.6 million)	339.0
Deposits	$ 307.0
Southern California [Member]
Subsequent Event [Line Items]
Business Combination, Number Of Branches Acquired	5
Northern California [Member]
Subsequent Event [Line Items]
Business Combination, Number Of Branches Acquired	1