Income Taxes - Reconciliation of Income Taxes Computed at Statutory Federal Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Line Items]
Income tax computed at federal statutory tax rate	21.00%	21.00%	21.00%
State taxes, net of federal benefit	5.90%	5.70%	6.10%
Research and development and other tax credits	3.80%	3.70%	4.90%
Stock based compensation	(0.60%)	(1.00%)	(0.60%)
Other	(0.20%)
Change in deferred tax asset valuation allowance	(29.90%)	50.50%	(31.40%)
Effective Income Tax Rate Reconciliation, Percent	0.00%
Federal
Income Tax Disclosure [Line Items]
Net operating loss - Section 382 Limitation		(28.10%)
Tax credit - Section 382 Limitation		(19.30%)
State
Income Tax Disclosure [Line Items]
Net operating loss - Section 382 Limitation		(25.50%)
Tax credit - Section 382 Limitation		(7.00%)