Quarterly report pursuant to Section 13 or 15(d)

Additional Cash Flow Information - Supplemental Disclosure of Cash Flow Information (Details)

v3.21.1
Additional Cash Flow Information - Supplemental Disclosure of Cash Flow Information (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Dec. 31, 2019
Supplemental Cash Flow Information [Abstract]        
Non-cash accruals of property, plant and equipment and other non-current assets $ (356) $ 2,174    
Non-cash settlement of withholding taxes associated with the 2019 bonus and vesting of certain awards 2,305 0    
Non-cash settlement of the 2019 bonus 3,258 0    
Non-cash settlement of Final Payment Fee 0 8,539    
Tradable equity securities 0 2,362    
Cash and cash equivalents 58,729 55,452 $ 78,297  
Non-current restricted cash 3,443 3,570 3,440  
Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 62,172 $ 59,022 $ 81,738 $ 68,482