Short-Term and Long-Term Investments - Summary of Investment (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	$ 182,418	$ 161,742
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	45,215	50,166
Other Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	2,639	2,517
US Treasury Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	45,215	70,164
US Treasury Obligations [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale		50,166
Auction Rate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	2,639	2,517
Auction Rate Securities [Member] | Other Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	2,639	2,517
Estimate of Fair Value Measurement [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	94,282	89,491
Estimate of Fair Value Measurement [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	45,215	50,166
Estimate of Fair Value Measurement [Member] | Other Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	2,639	2,517
Estimate of Fair Value Measurement [Member] | US Treasury Obligations [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale		19,998
Estimate of Fair Value Measurement [Member] | US Treasury Obligations [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale		50,166
Estimate of Fair Value Measurement [Member] | Auction Rate Securities [Member] | Other Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	2,639	2,517
Estimate of Fair Value Measurement [Member] | Money Market Funds [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	94,282	69,493
Estimate of Fair Value Measurement [Member] | US Treasury Obligations [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	45,215
Portion at Other than Fair Value Measurement [Member] | Cash [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-sale	$ 88,136	$ 72,251