8. Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred tax liabilities:
Net deferred tax assets	$ 7,407
Current
Deferred tax assets:
Operating loss carryforwards	2,098	1,224
R and D tax credit
AMT tax credit
Section 263A costs	534	496
Research and development costs	219	244
Amortization
Asset reserves:
Bad debts	14	16
Inventory reserve	1,009	987
Accrued expenses:
Non-qualified stock options
Compensation	208	187
Warranty	347	304
Deferred tax assets	4,429	3,458
Less valuation allowance
Less APIC pool reserve
Total deferred tax assets	4,429	3,458
Deferred tax liabilities:
Depreciation
Total deferred tax liabilities
Net deferred tax assets	4,429	3,458
Long Term
Deferred tax assets:
Operating loss carryforwards	1,369	3,109
R and D tax credit	860	860
AMT tax credit	251	202
Section 263A costs
Research and development costs	1,206	1,432
Amortization	19	15
Asset reserves:
Bad debts
Inventory reserve
Accrued expenses:
Non-qualified stock options	77	78
Compensation
Warranty
Deferred tax assets	3,782	5,696
Less valuation allowance	(14)	(250)
Less APIC pool reserve	(380)	(380)
Total deferred tax assets	3,388	5,066
Deferred tax liabilities:
Depreciation	(410)	(354)
Total deferred tax liabilities	(410)	(354)
Net deferred tax assets	$ 2,978	$ 4,712