Income Taxes - Additional Information (Details) - USD ($)		12 Months Ended
	Jun. 29, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Provision for income taxes		$ 0	$ 0
Valuation allowance		33,757,000	22,876,000
Federal net operating loss carryforwards		$ 108,100,000
Federal net operating loss carryforwards expire period		2034
State loss carryforwards		$ 71,400,000
State loss carryforwards expire period		2034
Foreign loss carryforwards		$ 600,000
Federal research and development tax credit carryforwards		3,200,000
State research and development tax credit carryforwards		$ 1,900,000
Federal research and development tax credit carryforwards expire period		2035
Cumulative change in ownership percentage		50.00%
Period for cumulative change in ownership		3 years
Unrecognized tax benefits		$ 874,000	$ 662,000	$ 479,000
Unrecognized tax benefits, interest or penalties		0
Unrecognized tax benefits, period increase (decrease)		0
After 2017
Income Taxes [Line Items]
Federal net operating loss carryforwards		$ 81,400,000
Net operating loss carryforwards, limitations		Net operating losses generated after December 31, 2017 are also subject to an 80% limitation if utilized after 2020.
Prior to 2017
Income Taxes [Line Items]
Federal net operating loss carryforwards		$ 26,700,000
Minimum | California Assembly Bill
Income Taxes [Line Items]
Adjusted gross income for taxable amount	$ 1,000,000
Maximum | California Assembly Bill
Income Taxes [Line Items]
Business credit offset amount	$ 5,000,000