Income Taxes (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Operating Loss Carryforwards [Line Items]    
Federal statutory income tax rate 21.00% 21.00%
Federal Operating loss carryforwards $ 534,200  
State Operating loss carryforwards 534,800  
Federal Operating loss carryforwards subject to expiration 37,200  
Federal Operating loss carryforwards subject to expiration indefinitely 497,000  
Research and development tax credit carryforwards 36,161 $ 23,524
Increase in gross deferred tax assets, before valuation allowance 65,800  
Accrued interest or penalties 0 0
Uncertain tax positions 0 $ 0
U.S. federal    
Operating Loss Carryforwards [Line Items]    
Research and development tax credit carryforwards 22,700  
State    
Operating Loss Carryforwards [Line Items]    
Research and development tax credit carryforwards $ 15,600