Short-Term and Long-Term Investments - Summary of Available-for-Sale Securities (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
US Treasury Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Cost	$ 45,238,000	$ 70,172,000
Gross Unrealized Losses	23,000	8,000
Estimated Fair Value	45,215,000	70,164,000
Failed Auction Security [Member]
Debt Securities, Available-for-sale [Line Items]
Cost	3,000,000	3,000,000
Gross Unrealized Losses	361,000	483,000
Estimated Fair Value	$ 2,639,000	$ 2,517,000