1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recent accounting pronouncements (Details) - ASU 2016-02 - Restatement $ in Millions	Mar. 31, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use assets, finance lease	$ 0.0
Lease liabilities, finance lease	0.0
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use assets, operating lease	1.0
Lease liabilities, operating lease	1.0
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use assets, operating lease	1.2
Lease liabilities, operating lease	$ 1.2