v3.20.4
Stockholders' Equity - Warrants (Details) - $ / shares
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Number of Warrants    
Number of warrants, granted, series B preferred stock (in shares)   9,262,500
Weighted Average Exercise Price per Warrant    
Weighted average exercise price per warrant, granted, series B preferred stock (in usd per share)   $ 1.62
Warrant    
Number of Warrants    
Warrant or right, outstanding, number, beginning balance (in shares) 30,527,776 17,818,844
Number of warrants, granted, marathon debt (in shares) 1,176,203 3,379,466
Number of warrants, granted, other (in shares)   66,966
Number of warrants, exercised (in shares) (30,502,763) 0
Number of warrants, expired (in shares) (45,540)  
Warrant or right, outstanding, number, beginning balance (in shares) 1,155,676 30,527,776
Weighted Average Exercise Price per Warrant    
Weighted average exercise price per warrant outstanding, beginning balance (in usd per share) $ 1.82 $ 1.84
Weighted average exercise price per warrant, granted, marathon debt (in usd per share) 28.26 2.26
Weighted average exercise price per warrant, granted, other (in usd per share)   5.28
Weighted average exercise price per warrant, exercised (in usd per share) 1.78 0
Weighted average exercise price per warrant, expired (in usd per share) 1.60  
Weighted average exercise price per warrant outstanding, ending balance (in usd per share) $ 28.74 $ 1.82