Available-for-Sale Debt Securities by Original Contractual Maturity (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
One year or less, amortized cost	$ 38,752	$ 42,598
Greater than one year and less than five years, amortized cost	22,901	17,858
Amortized Cost	61,653	60,456
One year or less, fair value	38,717	41,789
Greater than one year and less than five years, fair value	22,912	17,478
Total available-for-sale securities fair value	$ 61,629	$ 59,267