INCOME TAXES - Details of Significant Components of Net Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 4,936	$ 4,968
State income taxes	1	1
Deferred revenue	6,291	2,347
Research and development and other credits	8,282	9,590
Reserves and accruals recognized in different periods	1,128	3,734
Capitalized R&D expenses	3,447	3,415
Depreciation and amortization	3,636	472
Lease liability	806
Deferred rent	0	160
Other	0	6
Total deferred tax assets	28,527	24,693
Valuation allowance	(28,057)	(24,398)
Net deferred tax assets	470	295
Right of use lease assets	(466)
Foreign credits	(23)	(29)
Other	(40)	(17)
Net deferred tax liabilities	(529)	(46)
Net deferred taxes	$ (59)
Net deferred taxes		$ 249