Investments - Summary of Gross Unrealized Losses and Fair Value of Available-For-Sale Investment Securities in Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value	$ 270,873	$ 290,997
Less Than 12 Months, Unrealized Losses	(883)	(213)
Total, Estimated Fair Value	270,873	290,997
Total, Unrealized Losses	(883)	(213)
US Treasury Securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value	67,567	140,287
Less Than 12 Months, Unrealized Losses	(92)	(100)
Total, Estimated Fair Value	67,567	140,287
Total, Unrealized Losses	(92)	(100)
US Government Sponsored Enterprises Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value	49,502	49,512
Less Than 12 Months, Unrealized Losses	(92)	(38)
Total, Estimated Fair Value	49,502	49,512
Total, Unrealized Losses	(92)	(38)
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value	137,049	75,192
Less Than 12 Months, Unrealized Losses	(633)	(53)
Total, Estimated Fair Value	137,049	75,192
Total, Unrealized Losses	(633)	(53)
Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value	16,755
Less Than 12 Months, Unrealized Losses	(66)
Total, Estimated Fair Value	16,755
Total, Unrealized Losses	$ (66)
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value		26,006
Less Than 12 Months, Unrealized Losses		(22)
Total, Estimated Fair Value		26,006
Total, Unrealized Losses		$ (22)