1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recent accounting pronouncements (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Apr. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 617
Lease liabilities, operating lease	$ 640
ASU 2016-02 | Restatement
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 1,100
Lease liabilities, operating lease		$ 1,100