Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plan (Details Textual)

v3.8.0.1
Equity Incentive Plan (Details Textual) - USD ($)
1 Months Ended 12 Months Ended
Feb. 06, 2017
Jun. 30, 2017
Dec. 31, 2017
Dec. 27, 2017
Dec. 31, 2016
Jan. 31, 2017
Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]              
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized     $ 975,000   $ 984,000    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition     2 years 11 days   2 years 5 months 5 days    
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding And Exercisable Intrinsic Value     $ 191,000   $ 544,000    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights     vest 33.33% on the one-year anniversary of the grant date, and the remainder ratably over the 24-month period        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value     $ 78,000   207,000    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value     $ 640,000   $ 758,000    
Stock Issued During Period, Shares, Employee Stock Purchase Plans     158,000 53,477 0    
Share-based Compensation Arrangement by Share-based Payment Award, Description     Incentive stock options may be granted to any officer or employee at an exercise price per share of not less than the fair value per common share on the date of the grant (not less than 110% of fair value in the case of holders of more than 10% of the Companys voting stock) and with a term not to exceed ten years from the date of the grant (five years for incentive stock options granted to holders of more than 10% of the Companys voting stock).        
Equity Incentive Plan 2005 [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized             891,222
ESPP [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized   117,090 117,090        
Share-based Compensation Arrangement by Share-based Payment Award, Discount Price     $ 0        
Stock Issued During Period, Shares, Employee Stock Purchase Plans     158,000        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized   100,000          
2014 Plan [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant   1,690,123 116,411        
Excess Stock, Shares Authorized           405,235  
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized   250,000          
2014 Plan [Member] | Employee Stock Option [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant     568,450   377,771    
Restricted Stock [Member] | Eight Employees [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 104,000            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights These vest 33.33% on the one-year anniversary of the grant date, and the remainder ratably over the 24-month period following the one-year anniversary.            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period     1,000