Components Of Companys Deferred Tax Asset (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets-non current
Accrued bonuses	$ 0	$ 0
Accrued vacation	17	32
Net operating loss (NOL) carryover	7,516	9,166
Technology licenses amortization	36	60
Research & development tax credits	1,542	1,259
Share based expense	387	443
Other	5	9
Fixed asset depreciation	15	0
Total deferred tax asset	9,518	10,969
Less: valuation allowance	(9,518)	(10,965)
Net deferred tax asset	0	4
Deferred tax liability- non current	0	(4)
Net deferred tax asset	$ 0	$ 0