Net Income (Loss) Per Share 
6 Months Ended  

Jun. 30, 2017  
Earnings Per Share [Abstract]  
Earnings Per Share [Text Block] 
3. Net Income (Loss) Per Share
Basic net income (loss) per share excludes the effect of dilution and is computed by dividing net income (loss) by the weightedaverage number of shares outstanding for the period. Diluted net income (loss) per share reflects the potential dilution that could occur if securities or other contracts to issue shares were exercised into shares. In calculating diluted net income (loss) per share, the numerator is adjusted for the change in the fair value of the warrant liability (only if dilutive) and the denominator is increased to include the number of potentially dilutive common shares assumed to be outstanding during the period using the treasury stock method. The following table sets forth the reconciliation of the numerator and denominator used in the computation of basic and diluted net income (loss) per common share for the three and sixmonths ended June 30, 2017 and 2016:
The table below presents common shares underlying stock options and warrants that are excluded from the calculation of the weighted average number of common shares outstanding used for the calculation of diluted net income (loss) per common share. These are excluded from the calculation due to their antidilutive effect for the three and sixmonths ended June 30, 2017 and 2016:
