Income Taxes - Schedule of Reconciliation of Income Tax Expense Computed at Statutory Corporate Income Tax Rate to Effective Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Effective Income Tax Rate
Income tax expense at statutory rate	11.90%	11.90%	9.30%
State income tax, net of federal benefit	(1.00%)	1.00%	(2.10%)
Nondeductible expenses	0.70%	0.10%	(0.10%)
Foreign rate differential	0.60%	(0.10%)	2.00%
Statutory to US GAAP permanent differences	0.00%	0.00%	0.10%
Stock-based compensation	(2.50%)	2.30%	(2.00%)
Impact of deferred rate change	0.00%	0.00%	(12.20%)
Research credits	(4.20%)	3.30%	(5.20%)
Change in valuation allowance	(5.00%)	(18.70%)	10.90%
Effective income tax rate	0.50%	(0.20%)	0.70%