Fair Value Measurements - Fair Value Measurements of Cash Equivalents, Available-For-Sale Investment Securities and Equity Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	$ 364,673	$ 395,597
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Financial liabilities, fair value disclosure	2,129	898
Money market fund
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	81,485	72,578
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	130,939	95,703
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market fund
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	81,485	72,578
Significant Other Observable Inputs (Level 2)
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	233,734	299,894
Significant Unobservable Inputs (Level 3)
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Financial liabilities, fair value disclosure	2,129	898
U.S. Treasury notes
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	38,673	15,945
U.S. Treasury notes | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	38,673	15,945
Equity securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	10,781	7,180
Equity securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	10,781	7,180
US Government Sponsored Enterprises Debt Securities [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	226,351	94,803
US Government Sponsored Enterprises Debt Securities [Member] | Significant Other Observable Inputs (Level 2)
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	226,351	94,803
Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	7,383	20,775
Municipal bonds | Significant Other Observable Inputs (Level 2)
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure	7,383	20,775
Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure		184,316
Commercial paper | Significant Other Observable Inputs (Level 2)
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, fair value disclosure		184,316
Cash awards | Cash
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Financial liabilities, fair value disclosure	2,129	898
Cash awards | Significant Unobservable Inputs (Level 3) | Cash
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Financial liabilities, fair value disclosure	$ 2,129	$ 898