Income Taxes - Reconciliation Between Income Taxes at Statutory Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Income Taxes
Loss before income taxes	$ (10,882)	$ (8,599)
Tax (benefit) at statutory tax rate	(2,285)	(1,806)
Effects of:
Exclusion of incentive stock option expense	50	53
R&D tax credits	(832)	(290)
Increase (decrease) in valuation allowance	2,990	2,041
Carryforward adjustment	77	2
Provision for income taxes	0	$ 0
Unrecognized tax benefits	0
Unrecognized tax benefits, interest and penalties recorded	0
Unrecognized tax benefits, interest and penalties accrued	$ 0

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

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