Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	Additional Paid-in Capital	Additional Paid-in Capital Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Class A	Class A Common Stock	Class A Common Stock Conversion of Class B common stock to Class A common stock	Class A Common Stock Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	Class B	Class B Common Stock	Class B Common Stock Conversion of Class B common stock to Class A common stock	Class B Common Stock Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering
Beginning balance (in shares) at Dec. 31, 2022	73,021,449
Beginning balance at Dec. 31, 2022	$ 1,853,492
Ending balance (in shares) at Mar. 31, 2023	73,021,449
Ending balance at Mar. 31, 2023	$ 1,853,492
Beginning balance (in shares) at Dec. 31, 2022								6,381,936				51,410,111
Beginning balance at Dec. 31, 2022	(379,064)		$ 250,460		$ (3,792)	$ (625,738)		$ 0				$ 6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net (in shares)								111,488				23,926
Issuance of common stock upon exercise of stock options, net	963		963
Issuance of common stock upon settlement of restricted stock units, net (in shares)								221,612
Issuance of common stock upon settlement of restricted stock units, net	(4,229)		(4,229)
Stock-based compensation expense	12,480		12,480
Vesting of early exercised stock options	306		306
Net income (loss)	(60,866)					(60,866)	$ (7,015)				$ (53,851)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	2,495				2,495
Ending balance (in shares) at Mar. 31, 2023								6,715,036				51,434,037
Ending balance at Mar. 31, 2023	$ (427,915)		259,980		(1,297)	(686,604)		$ 0				$ 6
Beginning balance (in shares) at Dec. 31, 2023	73,021,449
Beginning balance at Dec. 31, 2023	$ 1,853,492
Total Convertible Preferred Stock
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering (in shares)	(73,021,449)
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	$ (1,853,492)
Beginning balance (in shares) at Dec. 31, 2023							7,099,700	7,099,700			53,904,204	53,904,204
Beginning balance at Dec. 31, 2023	$ (412,922)		302,820		814	(716,562)		$ 0				$ 6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net (in shares)	3,947,124							3,141,176				805,948
Issuance of common stock upon exercise of stock options, net	$ 23,089		23,089
Issuance of common stock upon settlement of restricted stock units, net (in shares)								6,173,372				624,115
Issuance of common stock upon settlement of restricted stock units, net	(202,852)		(202,853)					$ 1
Conversion of stock (in shares)									4,191,943	5,104,017			(4,191,943)	67,917,432
Conversion of stock		$ 1,853,492		$ 1,853,485						$ 1				$ 6
Issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs (in shares)								18,576,527
Issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs	576,268		576,266					$ 2
Stock-based compensation expense	577,508		577,508
Vesting of early exercised stock options	69		69
Net income (loss)	(575,066)					(575,066)	$ (92,094)				$ (482,972)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(1,286)				(1,286)
Ending balance (in shares) at Mar. 31, 2024							44,286,735	44,286,735			119,059,756	119,059,756
Ending balance at Mar. 31, 2024	$ 1,838,300		$ 3,130,384		$ (472)	$ (1,291,628)		$ 4				$ 12