Annual report pursuant to Section 13 and 15(d)

Convertible Preferred Stock and Stockholders' Equity - Warrants for common stock outstanding and exercisable (Details)

v3.20.4
Convertible Preferred Stock and Stockholders' Equity - Warrants for common stock outstanding and exercisable (Details) - Warrant [Member] - $ / shares
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Class of Stock [Line Items]    
Exercise Price $ 5.81  
Warrants Outstanding 7,314,102 1,454,826
Remaining Life (years) 4 years 6 months 15 days 2 years 7 months 13 days
Warrants Exercisable 7,299,102 1,454,826
Exercise Price Range One [Member]    
Class of Stock [Line Items]    
Warrants Outstanding 6,884,216 2,653,956
Remaining Life (years) 4 years 6 months 18 days 2 years 11 months 12 days
Warrants Exercisable 6,869,216 2,456,684
Exercise Price Range One [Member] | Minimum    
Class of Stock [Line Items]    
Exercise Price $ 2.32 $ 0.79
Exercise Price Range One [Member] | Maximum    
Class of Stock [Line Items]    
Exercise Price $ 3.90 $ 2.18
Exercise Price Range Two [Member]    
Class of Stock [Line Items]    
Warrants Outstanding 32,889 3,638,911
Remaining Life (years) 4 years 1 month 24 days 2 years 11 months 9 days
Warrants Exercisable 32,889 3,638,911
Exercise Price Range Two [Member] | Minimum    
Class of Stock [Line Items]    
Exercise Price $ 6.40 $ 3.00
Exercise Price Range Two [Member] | Maximum    
Class of Stock [Line Items]    
Exercise Price $ 9.80 $ 4.00
Exercise Price Range Three [Member]    
Class of Stock [Line Items]    
Warrants Outstanding 93,562 187,767
Remaining Life (years) 1 year 9 months 4 days 1 year 4 months 28 days
Warrants Exercisable 93,562 187,767
Exercise Price Range Three [Member] | Minimum    
Class of Stock [Line Items]    
Exercise Price $ 15.80 $ 4.50
Exercise Price Range Three [Member] | Maximum    
Class of Stock [Line Items]    
Exercise Price $ 17.50 4.95
Exercise Price Range Four Member [Member]    
Class of Stock [Line Items]    
Warrants Outstanding 230,571  
Remaining Life (years) 11 months 27 days  
Warrants Exercisable 230,571  
Exercise Price Range Four Member [Member] | Minimum    
Class of Stock [Line Items]    
Exercise Price $ 24.80 5.40
Exercise Price Range Four Member [Member] | Maximum    
Class of Stock [Line Items]    
Exercise Price $ 99.00 6.25
Exercise Price Range Five Member [Member]    
Class of Stock [Line Items]    
Exercise Price   $ 10.35
Warrants Outstanding 72,864 1,634
Remaining Life (years) 1 year 7 months 6 days 1 year 3 months 11 days
Warrants Exercisable 72,864 1,634
Exercise Price Range Six [Member]    
Class of Stock [Line Items]    
Exercise Price   $ 3.58
Warrants Outstanding   7,937,094
Remaining Life (years)   3 years
Warrants Exercisable   7,739,822