Marketable Securities - Amortized Cost vs. Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 862,513	$ 105,459
Fair Value	866,943	105,694
Cash equivalents
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	106,257	1,479
Gross Unrealized Gains	3	0
Gross Unrealized Losses	(1)	0
Fair Value	106,259	1,479
Cash equivalents \| Money market funds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	71,337	757
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	71,337	757
Cash equivalents \| U.S. treasury and agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	14,941	472
Gross Unrealized Gains	3	0
Gross Unrealized Losses	0	0
Fair Value	14,944	472
Cash equivalents \| Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	59
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	59
Cash equivalents \| Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	19,920	250
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	0
Fair Value	19,919	250
Marketable securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	756,256	103,980
Gross Unrealized Gains	4,492	321
Gross Unrealized Losses	(64)	(86)
Fair Value	760,684	104,215
Marketable securities \| U.S. treasury and agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	173,348	59,856
Gross Unrealized Gains	858	211
Gross Unrealized Losses	(14)	(64)
Fair Value	174,192	60,003
Marketable securities \| Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	418,602	23,552
Gross Unrealized Gains	3,335	96
Gross Unrealized Losses	(43)	(9)
Fair Value	421,894	23,639
Marketable securities \| Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	142,161	8,513
Gross Unrealized Gains	188	0
Gross Unrealized Losses	(6)	(5)
Fair Value	142,343	8,508
Marketable securities \| Foreign government bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	497
Gross Unrealized Gains	8
Gross Unrealized Losses	0
Fair Value	505
Marketable securities \| Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	21,648	12,059
Gross Unrealized Gains	103	14
Gross Unrealized Losses	(1)	(8)
Fair Value	$ 21,750	$ 12,065

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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