Elements of Deferred Income Tax Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets (liabilities)
- Depreciation & amortization	$ (236)	$ (412)
- Reserves for doubtful accounts	139	127
- Inventory reserve	304	250
- Non qualified stock options	247	108
- NOL	2,078	3,430
- AMT credit carryforward	0	160
Total	$ 2,500	$ 3,700