Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Abstract]
Fair Value	$ 1,288,253
Fair value, recurring
Cash and Cash Equivalents [Abstract]
Amortized Cost	611,749	$ 397,616
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(238)	(165)
Fair Value	611,512	397,451
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	1,289,837	845,109
Gross Unrealized Gains	26	615
Gross Unrealized Losses	(1,610)	(273)
Fair Value	1,288,253	845,451
Total assets measured at fair value, amortized cost	1,901,586	1,242,725
Total assets measured at fair value, gross unrealized gains	27	615
Total assets measured at fair value, gross unrealized losses	(1,848)	(438)
Total assets measured at fair value, fair value	1,899,765	1,242,902
Fair value, recurring | Cash | Level 1
Cash and Cash Equivalents [Abstract]
Amortized Cost	20,288	50,003
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	20,288	50,003
Fair value, recurring | Money market funds | Level 1
Cash and Cash Equivalents [Abstract]
Amortized Cost	107,073	47,357
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	107,073	47,357
Fair value, recurring | U.S. Treasury securities | Level 1
Cash and Cash Equivalents [Abstract]
Amortized Cost	44,734
Gross Unrealized Gains	0
Gross Unrealized Losses	(1)
Fair Value	44,733
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	734,969	481,704
Gross Unrealized Gains	0	422
Gross Unrealized Losses	(708)	(44)
Fair Value	734,261	482,082
Fair value, recurring | Commercial paper | Level 2
Cash and Cash Equivalents [Abstract]
Amortized Cost	437,660	300,256
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(237)	(165)
Fair Value	437,423	300,091
Fair value, recurring | Commercial paper | Level 2
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	132,929	102,435
Gross Unrealized Gains	0	7
Gross Unrealized Losses	(72)	(35)
Fair Value	132,857	102,407
Fair value, recurring | Corporate debt | Level 2
Cash and Cash Equivalents [Abstract]
Amortized Cost	1,994
Gross Unrealized Gains	1
Gross Unrealized Losses	0
Fair Value	1,995
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	272,753	133,523
Gross Unrealized Gains	26	168
Gross Unrealized Losses	(508)	(42)
Fair Value	272,271	133,649
Fair value, recurring | Asset-backed securities | Level 2
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	43,548	23,963
Gross Unrealized Gains	0	18
Gross Unrealized Losses	(25)	0
Fair Value	43,523	23,981
Fair value, recurring | U.S. government agency securities | Level 2
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	105,638	103,484
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(297)	(152)
Fair Value	$ 105,341	$ 103,332