Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Reconciliation between effective tax rate and federal statutory rate, percent
Federal income tax rate (as a percent)	21.00%	21.00%
Stock based compensation (as a percent)	(1.40%)	(2.20%)
Federal and state credits (as a percent)	2.70%	1.60%
State Taxes (as a percent)	5.00%	6.30%
Change in valuation allowance (as a percent)	(27.30%)	(26.50%)
Other (as a percent)		(0.20%)
Effective Tax Rate (as a percent)	0.00%	0.00%
Net operating loss carry-forwards	$ 16,406
Tax credit carry-forwards	1,254
Uncertain positions	0
Income tax related interest and penalties	$ 0

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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Amount of unrecognized tax benefits.

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