Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Line Items]
Income tax expense	$ 0	$ 0	$ 0
Unrecognized tax benefits	0	0
Unrecognized tax benefits, income tax penalties and interest accrued	$ 0	$ 0
Effective income tax rate reconciliation, tax credit, research and development, percentage	2.70%	4.10%	3.50%
Effective income tax rate reconciliation, tax credit, research and development (in usd)	$ 1,600,000	$ 1,800,000	$ 1,400,000
Federal
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards	$ 373,600,000	$ 205,100,000
Net operating loss carryforwards, expiration year	2037	2037
Operating losses carry forward, maximum deductibility percentage	80.00%
Federal tax credit carryforwards	$ 15,200,000	$ 10,100,000
Tax credit carryforwards, expiration year	2041	2041
State
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards	$ 346,900,000	$ 63,800,000
Federal tax credit carryforwards	$ 4,500,000	$ 2,700,000
Tax credit carryforwards, expiration year	2036	2036
Research and Development Tax Credits
Income Tax Disclosure [Line Items]
Increase in valuation allowance	$ 74,600,000	$ 27,800,000
Effective income tax rate reconciliation, tax credit, research and development, percentage	65.00%	65.00%	65.00%
Receivables relating to research and development credits	$ 3,400,000	$ 3,200,000