Annual report pursuant to Section 13 and 15(d)

Capitalization and Equity Structure - Schedule of Warrant Share Activity (Details)

v3.20.4
Capitalization and Equity Structure - Schedule of Warrant Share Activity (Details)
shares in Thousands
 1 Months Ended 12 Months Ended
Dec. 31, 2019
$ / shares
shares
Dec. 31, 2020
$ / shares
shares
Class Of Warrant Or Right, Outstanding [Roll Forward]    
Warrants outstanding (in shares)   1,178
Warrants issued (in shares)   996
Warrants expired (in shares)   (126)
Warrants exercised (in shares)   (723)
Warrants outstanding (in shares) 1,178 1,325
June 2020 Investor Warrants    
Schedule of Capitalization, Equity [Line Items]    
Exercise price (in dollars per share) | $ / shares   $ 5.18
Term (Years)   5 years 6 months
Class Of Warrant Or Right, Outstanding [Roll Forward]    
Warrants outstanding (in shares)   0
Warrants issued (in shares)   874
Warrants expired (in shares)   0
Warrants exercised (in shares)   (477)
Warrants outstanding (in shares) 0 397
June 2020 Placement Agent Warrants    
Schedule of Capitalization, Equity [Line Items]    
Exercise price (in dollars per share) | $ / shares   $ 5.64
Term (Years)   5 years
Class Of Warrant Or Right, Outstanding [Roll Forward]    
Warrants outstanding (in shares)   0
Warrants issued (in shares)   122
Warrants expired (in shares)   0
Warrants exercised (in shares)   0
Warrants outstanding (in shares) 0 122
December 2019 Warrants    
Schedule of Capitalization, Equity [Line Items]    
Exercise price (in dollars per share) | $ / shares   $ 8.10
Term (Years)   5 years
Class Of Warrant Or Right, Outstanding [Roll Forward]    
Warrants outstanding (in shares)   556
Warrants issued (in shares)   0
Warrants expired (in shares)   0
Warrants exercised (in shares)   0
Warrants outstanding (in shares) 556 556
December 2019 Placement Agent Warrants    
Schedule of Capitalization, Equity [Line Items]    
Exercise price (in dollars per share) | $ / shares $ 8.44  
Term (Years)   5 years
Class Of Warrant Or Right, Outstanding [Roll Forward]    
Warrants outstanding (in shares)   52
Warrants issued (in shares)   0
Warrants expired (in shares)   0
Warrants exercised (in shares)   0
Warrants outstanding (in shares) 52 52
May 2019 Warrants    
Schedule of Capitalization, Equity [Line Items]    
Exercise price (in dollars per share) | $ / shares   $ 3.52
Term (Years)   5 years
Class Of Warrant Or Right, Outstanding [Roll Forward]    
Warrants outstanding (in shares)   444
Warrants issued (in shares)   0
Warrants expired (in shares)   0
Warrants exercised (in shares)   (246)
Warrants outstanding (in shares) 444 198
2017 Information Agent Warrants    
Schedule of Capitalization, Equity [Line Items]    
Exercise price (in dollars per share) | $ / shares   $ 22.50
Term (Years)   3 years
Class Of Warrant Or Right, Outstanding [Roll Forward]    
Warrants outstanding (in shares)   13
Warrants issued (in shares)   0
Warrants expired (in shares)   (13)
Warrants exercised (in shares)   0
Warrants outstanding (in shares) 13 0
2015 Warrants    
Schedule of Capitalization, Equity [Line Items]    
Exercise price (in dollars per share) | $ / shares   $ 41.25
Term (Years)   5 years
Class Of Warrant Or Right, Outstanding [Roll Forward]    
Warrants outstanding (in shares)   107
Warrants issued (in shares)   0
Warrants expired (in shares)   (107)
Warrants exercised (in shares)   0
Warrants outstanding (in shares) 107 0
Pre-2014 warrants    
Schedule of Capitalization, Equity [Line Items]    
Exercise price (in dollars per share) | $ / shares   $ 144.90
Class Of Warrant Or Right, Outstanding [Roll Forward]    
Warrants outstanding (in shares)   6
Warrants issued (in shares)   0
Warrants expired (in shares)   (6)
Warrants exercised (in shares)   0
Warrants outstanding (in shares) 6 0
Pre-2014 warrants | Minimum    
Schedule of Capitalization, Equity [Line Items]    
Term (Years)   9 years
Pre-2014 warrants | Maximum    
Schedule of Capitalization, Equity [Line Items]    
Term (Years)   10 years