Quarterly report pursuant to Section 13 or 15(d)

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

v3.21.1
Convertible Preferred Stock and Stockholders' Equity - Warrants for common stock outstanding and exercisable (Details) - Warrant [Member] - $ / shares
 3 Months Ended 12 Months Ended
Mar. 31, 2021
Dec. 31, 2020
Exercise Price Range One [Member]    
Class of Stock [Line Items]    
Warrants Outstanding 5,103,384 6,884,216
Remaining Life (years) 4 years 3 months 22 days 4 years 6 months 18 days
Warrants Exercisable 5,088,384 6,869,216
Exercise Price Range One [Member] | Minimum    
Class of Stock [Line Items]    
Exercise Price $ 2.32 $ 2.32
Exercise Price Range One [Member] | Maximum    
Class of Stock [Line Items]    
Exercise Price $ 4.20 $ 3.90
Exercise Price Range Two [Member]    
Class of Stock [Line Items]    
Warrants Outstanding 32,889 32,889
Remaining Life (years) 3 years 10 months 28 days 4 years 1 month 24 days
Warrants Exercisable 32,889 32,889
Exercise Price Range Two [Member] | Minimum    
Class of Stock [Line Items]    
Exercise Price $ 6.40 $ 6.40
Exercise Price Range Two [Member] | Maximum    
Class of Stock [Line Items]    
Exercise Price $ 9.80 $ 9.80
Exercise Price Range Three [Member]    
Class of Stock [Line Items]    
Warrants Outstanding 93,562 93,562
Remaining Life (years) 1 year 6 months 4 days 1 year 9 months 4 days
Warrants Exercisable 93,562 93,562
Exercise Price Range Three [Member] | Minimum    
Class of Stock [Line Items]    
Exercise Price $ 15.80 $ 15.80
Exercise Price Range Three [Member] | Maximum    
Class of Stock [Line Items]    
Exercise Price $ 17.50 $ 17.50
Exercise Price Range Four Member [Member]    
Class of Stock [Line Items]    
Warrants Outstanding 227,901 230,571
Remaining Life (years) 1 year 1 month 10 days 11 months 27 days
Warrants Exercisable 227,901 230,571
Exercise Price Range Four Member [Member] | Minimum    
Class of Stock [Line Items]    
Exercise Price $ 24.80 $ 24.80
Exercise Price Range Four Member [Member] | Maximum    
Class of Stock [Line Items]    
Exercise Price $ 99.00 $ 99.00
Exercise Price Range Five Member [Member]    
Class of Stock [Line Items]    
Warrants Outstanding 72,864 72,864
Remaining Life (years) 1 year 4 months 6 days 1 year 7 months 6 days
Warrants Exercisable 72,864 72,864
Exercise Price Range Five Member [Member] | Minimum    
Class of Stock [Line Items]    
Exercise Price $ 108.00 $ 108.00
Exercise Price Range Five Member [Member] | Maximum    
Class of Stock [Line Items]    
Exercise Price 207.00 207.00
Exercise Price Range Six [Member]    
Class of Stock [Line Items]    
Exercise Price $ 6.90 $ 5.81
Warrants Outstanding 5,530,600 7,314,102
Remaining Life (years) 4 years 2 months 12 days 4 years 6 months 15 days
Warrants Exercisable 5,515,600 7,299,102