XML 44 R28.htm IDEA: XBRL DOCUMENT v3.19.1
Note 11 - Net Loss Per Share Attributable to Common Stockholders (Tables)
12 Months Ended
Dec. 31, 2018
Notes Tables  
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]
    Year Ended December 31,
    2018   2017   2016
Outstanding stock options    
4,597,226
     
2,681,072
     
2,166,254
 
Convertible preferred stock    
22,112,775
     
22,112,775
     
-
 
     
26,710,001
     
24,793,847
     
2,166,254