Cash, Cash Equivalents, Restricted Cash And Investments - Schedule of Contractual Maturity Date of Cash Cash Equivalents, Restricted Cash and Investments in Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Line Items]
1 Year or Less	$ 383,990
Greater than 1 Year	103,531
Total	487,521	$ 539,798
Cash and money market funds [Member]
Cash and Cash Equivalents [Line Items]
1 Year or Less	5,614
Greater than 1 Year	2,416
Total	8,030	46,367
Commercial Paper [Member]
Cash and Cash Equivalents [Line Items]
1 Year or Less	39,980
Greater than 1 Year	0
Total	39,980	129,698
Corporate Notes and Bonds [Member]
Cash and Cash Equivalents [Line Items]
1 Year or Less	133,242
Greater than 1 Year	65,113
Total	198,355	271,210
Municipal Bonds [Member]
Cash and Cash Equivalents [Line Items]
1 Year or Less	4,873
Greater than 1 Year	0
Total	4,873	9,632
US government and agency [Member]
Cash and Cash Equivalents [Line Items]
1 Year or Less	200,281
Greater than 1 Year	36,002
Total	$ 236,283	$ 82,891