SUBSEQUENT EVENTS (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 3,371	$ 4,048	$ 0
Net book values	1,768		$ 2,343
Operating lease liabilities	4,082	$ 4,850
50 Rio Robles in San Jose, California
Lessee, Lease, Description [Line Items]
Right-of-use assets	2,400
Operating lease liabilities	3,000
50 Rio Robles in San Jose, California | Leasehold improvements
Lessee, Lease, Description [Line Items]
Net book values	1,100
50 Rio Robles in San Jose, California | Furniture and fixtures
Lessee, Lease, Description [Line Items]
Net book values	$ 100