CONSOLIDATED STATEMENTS OF SHAREHOLDERS' DEFICIT - USD ($) shares in Thousands, $ in Thousands	Ordinary Shares	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Balances at Dec. 31, 2019	$ 1	$ 1,024,614	$ 145	$ (1,248,600)	$ (223,840)
Balances (in shares) at Dec. 31, 2019	57,015
Increase (Decrease) in Stockholders' Equity
Net proceeds from sale of ordinary shares		139,915			139,915
Net proceeds from sale of ordinary shares (in shares)	5,500
Proceeds from ESPP purchases		3,701			3,701
Proceeds from ESPP purchases (in shares)	245
Employee share-based compensation expense		62,976			62,976
Issuance of restricted shares (in shares)	1,907
Option exercises		1,361			1,361
Option exercises (in shares)	68
Repurchase of shares to satisfy tax withholding		(9,749)			(9,749)
Repurchase of shares to satisfy tax withholding (in shares)	(407)
Net unrealized loss on marketable securities			(98)		(98)
Net income (loss)				(278,017)	(278,017)
Balances at Dec. 31, 2020	$ 1	1,222,818	47	(1,526,617)	(303,751)
Balances (in shares) at Dec. 31, 2020	64,328
Increase (Decrease) in Stockholders' Equity
Net proceeds from sale of ordinary shares		108,180			108,180
Net proceeds from sale of ordinary shares (in shares)	7,705
Proceeds from ESPP purchases		3,466			3,466
Proceeds from ESPP purchases (in shares)	275
Employee share-based compensation expense		62,061			62,061
Issuance of restricted shares (in shares)	2,682
Option exercises		5			5
Repurchase of shares to satisfy tax withholding		(9,061)			(9,061)
Repurchase of shares to satisfy tax withholding (in shares)	(555)
Net unrealized loss on marketable securities			(47)		(47)
Net income (loss)				(199,426)	(199,426)
Balances at Dec. 31, 2021	$ 1	1,387,469		(1,726,043)	$ (338,573)
Balances (in shares) at Dec. 31, 2021	74,435				74,435
Increase (Decrease) in Stockholders' Equity
Repurchase of ordinary shares, net of transaction costs		(128,830)			$ (128,830)
Repurchase of ordinary shares, net of transaction costs (in shares)	(12,739)
Proceeds from ESPP purchases		802			802
Proceeds from ESPP purchases (in shares)	118
Employee share-based compensation expense		39,734			39,734
Issuance of restricted shares (in shares)	3,764
Repurchase of shares to satisfy tax withholding		(3,450)			(3,450)
Repurchase of shares to satisfy tax withholding (in shares)	(351)
Net unrealized loss on marketable securities			(15)		(15)
Net income (loss)				872,132	872,132
Balances at Dec. 31, 2022	$ 1	$ 1,295,725	$ (15)	$ (853,911)	$ 441,800
Balances (in shares) at Dec. 31, 2022	65,227				65,227