ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration of Credit Risk (Details)	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Customer concentration \| Loan portfolio
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Concentration risk (as a percent)	72.60%	73.60%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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