Summary of Available-for-Sale Securities (Detail) - USD ($)	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 61,653,000	$ 60,456,000
Gross Unrealized Gain	250,000	26,000
Gross Unrealized Loss	(274,000)	(1,215,000)
Allowance for Credit Loss	0	0	$ 0
Fair Value	61,629,000	59,267,000
Money market funds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,639,000	5,062,000
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Allowance for Credit Loss	0	0
Fair Value	7,639,000	5,062,000
United States government agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	23,819,000	19,652,000
Gross Unrealized Gain	120,000	16,000
Gross Unrealized Loss	(37,000)	(314,000)
Allowance for Credit Loss	0	0
Fair Value	23,902,000	19,354,000
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	27,047,000	32,395,000
Gross Unrealized Gain	119,000	3,000
Gross Unrealized Loss	(37,000)	(638,000)
Allowance for Credit Loss	0	0
Fair Value	27,129,000	31,760,000
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,148,000	3,347,000
Gross Unrealized Gain	11,000	7,000
Gross Unrealized Loss	(200,000)	(263,000)
Allowance for Credit Loss	0	0
Fair Value	$ 2,959,000	$ 3,091,000