Cash, Cash Equivalents, Restricted Cash And Investments - Summary of Unrealized Gains and Losses and Estimated Fair Value of Cash Equivalents and Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Line Items]
Amortized Cost	$ 517,392	$ 547,153
Gross Unrealized Gains	1	42
Gross Unrealized Losses	(6,088)	(7,397)
Estimated Fair Value	511,305	539,798
Cash and money market funds [Member]
Cash and Cash Equivalents [Line Items]
Amortized Cost	16,086	46,367
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	16,086	46,367
Commercial Paper [Member]
Cash and Cash Equivalents [Line Items]
Amortized Cost	81,193	130,141
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(150)	(443)
Estimated Fair Value	81,043	129,698
Corporate Notes And Bonds [Member]
Cash and Cash Equivalents [Line Items]
Amortized Cost	222,936	277,184
Gross Unrealized Gains	0	19
Gross Unrealized Losses	(4,582)	(5,993)
Estimated Fair Value	218,354	271,210
Municipal Bonds [Member]
Cash and Cash Equivalents [Line Items]
Amortized Cost	9,965	9,905
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(162)	(273)
Estimated Fair Value	9,803	9,632
US Government Corporations and Agencies Securities [Member]
Cash and Cash Equivalents [Line Items]
Amortized Cost	187,212	83,556
Gross Unrealized Gains	1	23
Gross Unrealized Losses	(1,194)	(688)
Estimated Fair Value	$ 186,019	$ 82,891