Difference Between Provision for Income Taxes and Amounts Computed by Applying Federal Statutory Income Tax Rate to Loss before Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal statutory tax	$ (4,359)	$ (7,838)	$ (8,891)
Federal research credits	(853)	(1,065)	(1,874)
State research credits	(767)	(642)	(822)
Expiration of federal carryovers	5,206	7,284	4,858
Change in valuation allowance	(2,357)	1,361	6,379
Compensation related items	4,015	3,257	1,794
State taxes	(259)	(1,710)	(1,127)
Revision to prior year items	(676)	(664)
Other	255	342	171
Provision for income taxes	$ 205	$ 325	$ 488