Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
COVID-19 Risks, Impacts and Uncertainties
Net income (loss)	$ (3,373)	$ (184)	$ (8,865)	$ (66)
Cash and cash equivalents	$ 8,753	$ 30,993	8,753	30,993	$ 28,577
Proceeds from the issuance of common stock			$ 80	$ 83