8. Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax liabilities:
Net deferred tax assets	$ 6,909
Current
Deferred tax assets:
Operating loss carryforwards	1,542	2,098
R and D tax credit
AMT tax credit
Section 263A costs	535	534
Research and development costs	219	219
Amortization
Asset reserves:
Bad debts	30	14
Inventory reserve	1,058	1,009
Accrued expenses:
Non-qualified stock options
Compensation	199	208
Warranty	253	347
Deferred tax assets	3,836	4,429
Less valuation allowance
Less APIC pool reserve
Total deferred tax assets	3,836	4,429
Deferred tax liabilities:
Depreciation
Amortization
Total deferred tax liabilities
Net deferred tax assets	3,836	4,429
Long Term
Deferred tax assets:
Operating loss carryforwards	1,651	1,369
R and D tax credit	951	860
AMT tax credit	266	251
Section 263A costs
Research and development costs	1,209	1,206
Amortization		19
Asset reserves:
Bad debts
Inventory reserve
Accrued expenses:
Non-qualified stock options	78	77
Compensation
Warranty
Deferred tax assets	4,155	3,782
Less valuation allowance		(14)
Less APIC pool reserve	(380)	(380)
Total deferred tax assets	3,775	3,388
Deferred tax liabilities:
Depreciation	(507)	(410)
Amortization	(196)
Total deferred tax liabilities	(507)	(410)
Net deferred tax assets	$ 3,072	$ 2,978