Accrued Expenses and Long-term Liabilities - Schedule of Long Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Warrant liability	$ 21	$ 82
Uncertain tax positions	4,342	4,081
Deferred revenue	136	269
Other	138	141
Total other long-term liabilities	$ 4,637	$ 4,573