Income Taxes - Significant Components of Company's Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating losses	$ 27,867	$ 19,440
Research and development credits	3,913	2,784
Lease liability	489	657
Depreciation and amortization	242	183
Other accruals and prepaid expenses	1,688	428
Total gross deferred tax assets	34,199	23,492
Less: Valuation allowance	(33,757)	(22,876)
Deferred tax assets, net	442	616
Deferred tax liabilities:
Right-of-use asset	(442)	(616)
Total gross deferred tax liabilities	$ (442)	$ (616)