CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance (in shares) at Dec. 31, 2018	308,373
Balance at Dec. 31, 2018	$ 1,465,399
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of redeemable convertible preferred stock and redeemable convertible preferred stock warrants to common stock in connection with initial public offering (in shares)	(308,373)
Conversion of redeemable convertible preferred stock and redeemable convertible preferred stock warrants to common stock in connection with initial public offering	$ (1,465,399)
Balance (in shares) at Dec. 31, 2019	0
Balance at Dec. 31, 2019	$ 0
Beginning balance (in shares) at Dec. 31, 2018		127,298
Beginning balance at Dec. 31, 2018	(594,563)	$ 1	$ 252,212	$ (1,421)	$ (845,355)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Release of restricted stock units (in shares)		28,084
Release of restricted stock units	1	$ 1
Shares repurchased for tax withholdings on release of restricted stock units	(475,015)		(475,015)
Conversion of redeemable convertible preferred stock and redeemable convertible preferred stock warrants to common stock in connection with initial public offering (in shares)		308,622
Conversion of redeemable convertible preferred stock and redeemable convertible preferred stock warrants to common stock in connection with initial public offering	1,470,077	$ 3	1,470,074
Issuance of common stock in connection with initial public offering net of underwriters' discounts and commissions and offering costs (in shares)		86,250
Issuance of common stock in connection with initial public offering net of underwriters' discounts and commissions and offering costs	1,563,383	$ 1	1,563,382
Issuance of common stock for cash upon exercise of stock options, net (in shares)		19,650
Issuance of common stock for cash upon exercise of stock options, net	41,344		41,344
Share-based compensation	1,377,781		1,377,781
Other comprehensive income (loss)	2,068			2,068
Net income (loss)	(1,361,371)				(1,361,371)
Ending balance (in shares) at Dec. 31, 2019		569,904
Ending balance at Dec. 31, 2019	$ 2,023,705	$ 6	4,229,778	647	(2,206,726)
Balance (in shares) at Dec. 31, 2020	0
Balance at Dec. 31, 2020	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Release of restricted stock units (in shares)		19,890
Shares repurchased for tax withholdings on release of restricted stock units	(56,894)		(56,894)
Issuance of common stock for cash upon exercise of stock options, net (in shares)		34,149
Issuance of common stock for cash upon exercise of stock options, net	78,282		78,282
Issuance of common stock related to charitable contributions (in shares)		150
Issuance of common stock related to charitable contributions	2,748		2,748
Issuance of restricted stock awards, net (in shares)		2,279
Share-based compensation	321,020		321,020
Other comprehensive income (loss)	1,833			1,833
Net income (loss)	(128,323)				(128,323)
Ending balance (in shares) at Dec. 31, 2020		626,372
Ending balance at Dec. 31, 2020	$ 2,242,371	$ 6	4,574,934	2,480	(2,335,049)
Balance (in shares) at Dec. 31, 2021	0
Balance at Dec. 31, 2021	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Release of restricted stock units (in shares)		21,724
Release of restricted stock units	$ 1	$ 1
Issuance of common stock for cash upon exercise of stock options, net (in shares)	7,806	7,806
Issuance of common stock for cash upon exercise of stock options, net	$ 23,912		23,912
Issuance of common stock related to charitable contributions (in shares)		750
Issuance of common stock related to charitable contributions	45,300		45,300
Issuance of restricted stock awards, net (in shares)		220
Share-based compensation	415,382		415,382
Other comprehensive income (loss)	(4,661)			(4,661)
Net income (loss)	316,438				316,438
Ending balance (in shares) at Dec. 31, 2021		656,872
Ending balance at Dec. 31, 2021	$ 3,038,743	$ 7	$ 5,059,528	$ (2,181)	$ (2,018,611)