Annual report pursuant to Section 13 and 15(d)

Income Taxes - Reconciliation - (Details)

v3.20.4
Income Taxes - Reconciliation - (Details)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Tax Disclosure [Abstract]      
Federal income tax computed at federal statutory tax rate 21.00% 21.00% 21.00%
State income tax, net of federal benefit 6.12% 6.56% 6.01%
Permanent items (0.68%) (0.89%) (0.61%)
Federal and state research and development credits 3.89% 4.79% 4.79%
Other (0.88%) (0.77%) 0.01%
Change in valuation allowance (29.45%) (30.73%) (31.24%)
Effective income tax rate   (0.04%) (0.04%)