Income Taxes (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Income (loss) before income taxes:      
Domestic $ 7,464,000 $ 3,633,000 $ (4,055,000)
Foreign 1,103,000 118,000 473,000
Income (loss) before income taxes 8,567,000 3,751,000 (3,582,000)
Domestic      
Federal 76,000 64,000 15,000
State 52,000 53,000 57,000
Foreign 288,000 147,000 69,000
Total current tax expense 416,000 264,000 141,000
Domestic      
Federal 1,761,000 1,572,000 (710,000)
State 30,000 44,000 (65,000)
Foreign (5,000) (16,000) 88,000
Valuation allowance (1,791,000) (1,616,000) 687,000
Total deferred tax benefit (5,000) (16,000)  
Total income tax expense 411,000 248,000 141,000
Reconciliation from the U.S. statutory federal income tax rate to the effective income tax rate      
U.S. federal statutory rate (as a percent) 34.00% 34.00% (34.00%)
State taxes, net of federal benefit (as a percent) 0.40% 1.10% 1.10%
Stock-based compensation (as a percent) (2.10%) 22.70% 15.00%
Stock warrant (as a percent)   6.40%  
Research and development credits (as a percent) (8.10%) (18.30%)  
Change in valuation allowance (as a percent) (20.60%) (42.00%) 17.30%
Other, net (as a percent) 1.20% 2.70% 4.50%
Effective income tax rate (as a percent) 4.80% 6.60% 3.90%
Deferred Tax Assets:      
Reserves and accruals 1,449,000 2,146,000  
Inventories 1,063,000 1,059,000  
Net operating loss carryforwards 25,007,000 27,865,000  
Property, plant and equipment 1,831,000 1,327,000  
Stock-based compensation 1,540,000 1,233,000  
Research and development credit carryforwards 5,243,000 4,091,000  
Other   163,000  
Total deferred tax assets 36,133,000 37,884,000  
Valuation allowance (36,050,000) (37,842,000)  
Total deferred tax assets, net 83,000 42,000  
Deferred Tax Liabilities:      
Undistributed earnings of foreign subsidiaries (56,000) (15,000)  
Intangible Assets (116,000)    
Property and equipment (16,000) (11,000)  
Total deferred tax liabilities (188,000) (26,000)  
Net deferred tax asset (liability) (105,000) 16,000  
Increase (decrease) in net valuation allowance $ (1,800,000) $ (1,600,000)