Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2024		132,646
Beginning balance at Dec. 31, 2024	$ 1,195,420	$ 12	$ 3,763,614	$ (2,567,862)	$ (344)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		134
Issuance of common stock upon exercise of stock options	2,819		2,819
Issuance of common stock under the employee stock purchase plan (in shares)		116
Issuance of common stock under the employee stock purchase plan	12,236		12,236
Issuance of common stock for bonus (in shares)		228
Issuance of common stock for bonus	32,875		32,875
Vesting of restricted stock units (in shares)		4,409
Vesting of restricted stock units	2	$ 2
Stock-based compensation	264,097		264,097
Unrealized gain on available-for sale securities, net of tax and foreign currency translation adjustment	157				157
Net loss	(255,418)			(255,418)
Ending balance (in shares) at Sep. 30, 2025		137,533
Ending balance at Sep. 30, 2025	1,252,188	$ 14	4,075,641	(2,823,280)	(187)
Beginning balance (in shares) at Jun. 30, 2025		136,757
Beginning balance at Jun. 30, 2025	1,246,182	$ 14	3,982,191	(2,735,736)	(287)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		65
Issuance of common stock upon exercise of stock options	1,935		1,935
Vesting of restricted stock units (in shares)		711
Stock-based compensation	91,515		91,515
Unrealized gain on available-for sale securities, net of tax and foreign currency translation adjustment	100				100
Net loss	(87,544)			(87,544)
Ending balance (in shares) at Sep. 30, 2025		137,533
Ending balance at Sep. 30, 2025	$ 1,252,188	$ 14	4,075,641	(2,823,280)	(187)
Beginning balance (in shares) at Dec. 31, 2025	139,693	139,693
Beginning balance at Dec. 31, 2025	$ 1,712,413	$ 14	4,488,679	(2,776,022)	(258)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	479	479
Issuance of common stock upon exercise of stock options	$ 5,736		5,736
Issuance of common stock under the employee stock purchase plan (in shares)		97
Issuance of common stock under the employee stock purchase plan	16,430		16,430
Issuance of common stock for bonus (in shares)		229
Issuance of common stock for bonus	47,026		47,026
Cash paid to satisfy statutory withholding requirement for net settlement of cashless stock option exercises (in shares)		(28)
Cash paid to satisfy statutory withholding requirement for net settlement of cashless stock option exercises	(5,413)		(5,413)
Vesting of restricted stock units (in shares)		3,866
Issuance of common stock pursuant to asset acquisition, net (in shares)		10
Issuance of common stock pursuant to asset acquisition, net	2,000		2,000
Cancellation of escrow shares pursuant to business combination, net (in shares)		(1)
Cancellation of escrow shares pursuant to business combination, net	(323)		(323)
Stock-based compensation	303,531		303,531
Unrealized gain on available-for sale securities	130				130
Net loss	$ (211,972)			(211,972)
Ending balance (in shares) at Sep. 30, 2026	144,345	144,345
Ending balance at Sep. 30, 2026	$ 1,869,558	$ 14	4,857,666	(2,987,994)	(128)
Beginning balance (in shares) at Jun. 30, 2026		143,612
Beginning balance at Jun. 30, 2026	1,821,499	$ 14	4,749,675	(2,928,082)	(108)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		25
Issuance of common stock upon exercise of stock options	941		941
Cash paid to satisfy statutory withholding requirement for net settlement of cashless stock option exercises	(316)		(316)
Vesting of restricted stock units (in shares)		708
Stock-based compensation	107,366		107,366
Unrealized gain on available-for sale securities, net of tax and foreign currency translation adjustment	(20)				(20)
Net loss	$ (59,912)			(59,912)
Ending balance (in shares) at Sep. 30, 2026	144,345	144,345
Ending balance at Sep. 30, 2026	$ 1,869,558	$ 14	$ 4,857,666	$ (2,987,994)	$ (128)