9. Income Taxes (Details 2) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Operating loss carryforwards	$ 1,035	$ 2,263
R&D tax credit	1,310	1,195
AMT tax credit	364	303
Section 263A costs	502	552
R&D costs	690	861
Amortization	34	33
Asset reserves:
Bad debts	18	18
Inventory reserve	574	601
Accrued expenses:
Non-qualified stock options	86	78
Compensation	261	240
Warranty	415	368
Deferred tax assets	5,289	6,512
Less valuation allowance	(76)	0
Less APIC pool allowance	0	(380)
Total deferred tax assets	5,213	6,132
Deferred tax liabilities:
Depreciation	(626)	(426)
Unrealized gain	(1,169)	(245)
Total deferred tax liabilities	(1,795)	(671)
Net deferred tax assets	$ 3,418	$ 5,461