INCOME TAXES - Details of Significant Components of Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Net operating loss carryforwards	$ 4,785	$ 5,391
State income taxes	50	15
Deferred revenue	2,769	3,498
Research and development and other credits	3,701	3,757
Reserve and accruals recognized in different periods	(563)	1,692
Capitalized research and development expenses	2,850	3,019
Depreciation and amortization	587	1,802
Lease liability	7	104
Total deferred tax assets	14,186	19,278
Valuation allowance	(10,837)	(12,341)
Net deferred tax assets	3,349	6,937
Deferred tax liabilities:
Right of use lease assets	(6)	(67)
Total deferred tax liabilities	(6)	(67)
Net deferred taxes	$ 3,343	$ 6,870