Income Taxes - Summary of provision for income taxes was different from the amount computed using the federal statutory rate (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Effective Income Tax Rate Reconciliation, Amount [Abstract]    
Income tax provision at federal statutory rate (21%) $ (28,642) $ (76,385)
Interest on convertible securities 6,537 3,505
Interest on convertible securities discount 4,423 3,257
Debt issuance cost related to convertible securities 0 76
Derivative liability related to convertible securities (19,688) 29,098
Warrant expense 16,823 596
Meals and entertainment 13 210
Health insurance industry fee 2,715 0
Other, net (766) 0
Valuation allowance 18,585 39,643
Provision for income taxes $ 0 $ 0