Organization and Business - Liquidity and Going Concern (Details) - USD ($) $ in Thousands	1 Months Ended
	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization and Business
Accumulated deficit		$ (166,899)	$ (133,090)
Amount reduced of outstanding balance of a secured promissory note	$ 1,800
Amount raised from registered public offering	$ 20,500
Cash		$ 33,800