DEBT - Summary of Debt (Details) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
May 20, 2020
Sep. 09, 2014
Debt Instrument [Line Items]        
Total principal amount $ 73,493 $ 84,118    
Unamortized debt discounts 0 (16)    
Carrying value 73,493 84,102    
Less: current portion of long-term debt (12,174) (11,942)    
Long-term debt $ 61,319 72,160    
Senior Notes | 13% Senior Secured Note due 2024        
Debt Instrument [Line Items]        
Interest rate 13.00%   13.00%  
Total principal amount $ 70,750 80,250    
Less: current portion of long-term debt (9,500)      
Long-term debt 61,300      
Senior Notes | Royalty rights obligation        
Debt Instrument [Line Items]        
Total principal amount $ 2,743 3,533    
Convertible debt | 2.50% Convertible Notes due 2021        
Debt Instrument [Line Items]        
Interest rate 2.50%     2.50%
Total principal amount $ 0 335    
Carrying value $ 0 $ 300