Accrued Expenses and Other Current Liabilities - Summary of Accrued Severance Costs (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Restructuring Reserve [Roll Forward]    
Balance at beginning of the year $ 56 $ 274
Charged to expense 970 607
Balance at end of year 21 56
2018 Restructuring Plan    
Restructuring Reserve [Roll Forward]    
Cash payments 0 (268)
2019 Restructuring Plan    
Restructuring Reserve [Roll Forward]    
Cash payments (56) (557)
2020 Restructuring Plan    
Restructuring Reserve [Roll Forward]    
Cash payments $ (949) $ 0