Contractual Maturities of Investments in Debt Securities Held (Detail) $ in Thousands	Dec. 31, 2023 USD ($)
Schedule of Available-for-sale Securities
Due within one year, cost	$ 62,385
Due after 1 year through 5 years, cost	23,703
Due after 5 years through 10 years, cost	6,049
Due after 10 years, cost	39,159
Total, cost	131,296
Due within one year, fair market value	62,154
Due after 1 year through 5 years, fair market value	23,319
Due after 5 years through 10 years, fair market value	5,735
Due after 10 years, fair maket value	32,475
Total, fair market value	$ 123,683