Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Net operating loss carryforward	$ 64,531	$ 51,708
Intangible assets	57	51
Accrued expense	846	598
Stock-based compensation	2,767	2,087
Other	220	299
Total deferred tax assets	87,991	70,346
Deferred tax liabilities
Depreciable assets	(948)	(203)
Total deferred tax liabilities	(948)	(203)
Less: Valuation allowance	(87,043)	(70,143)
Deferred tax assets, net	0	0
Domestic Country Member
Deferred tax assets
Tax credits	18,579	14,764
State And Local Jurisdiction Member
Deferred tax assets
Tax credits	$ 991	$ 839