Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Shares [Member]	Treasury Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2018	$ 392,195	$ 1,584	$ (57)	$ 682,245	$ (291,569)	$ (8)
Beginning balance (in shares) at Dec. 31, 2018		51,852,862	307,936
Issuance of common shares, net of issuance costs	414,789	$ 230		414,559
Issuance of common shares, net of issuance costs (in shares)		7,704,068	(47,297)
Vesting of restricted shares	43	$ 2		41
Vesting of restricted shares (in shares)		68,009
Exercise of vested options, net of issuance costs	16,001	$ 31	$ (6)	15,976
Exercise of vested options, net of issuance costs (in shares)		1,158,860	(10,413)
Stock-based compensation expense	49,524			49,524
Other comprehensive income (loss)	15					15
Net income (loss)	66,858				66,858
Ending balance at Dec. 31, 2019	939,425	$ 1,847	$ (63)	1,162,345	(224,711)	7
Ending balance (in shares) at Dec. 31, 2019		60,783,799	250,226
Issuance of common shares, net of issuance costs	973,381	$ 366		973,015
Issuance of common shares, net of issuance costs (in shares)		11,412,519
Vesting of restricted shares	7	$ 7
Vesting of restricted shares (in shares)		204,650
Exercise of vested options, net of issuance costs	32,775	$ 57		32,718
Exercise of vested options, net of issuance costs (in shares)		1,482,636	(37,080)
Purchase of common stock under ESPP	694			694
Purchase of common stock under ESPP (in shares)		13,410
Stock-based compensation expense	66,018			66,018
Issuance of common stock for license agreements	889			889
Issuance of common stock for license agreements (in shares)		17,830	(17,830)
Other comprehensive income (loss)	(90)					(90)
Net income (loss)	(348,865)				(348,865)
Ending balance at Dec. 31, 2020	1,664,234	$ 2,277	$ (63)	2,235,679	(573,576)	(83)
Ending balance (in shares) at Dec. 31, 2020		73,914,844	195,316
Issuance of common shares, net of issuance costs	222,175	$ 45		222,130
Issuance of common shares, net of issuance costs (in shares)		1,353,121
Vesting of restricted shares	15	$ 15
Vesting of restricted shares (in shares)		455,440
Exercise of vested options, net of issuance costs	$ 35,874	$ 54		35,820
Exercise of vested options, net of issuance costs (in shares)	1,245,071	1,245,071	(15,000)
Purchase of common stock under ESPP	$ 2,095			2,095
Purchase of common stock under ESPP (in shares)		21,590
Stock-based compensation expense	102,390			102,390
Other comprehensive income (loss)	(4,984)					(4,984)
Net income (loss)	377,661				377,661
Ending balance at Dec. 31, 2021	$ 2,399,460	$ 2,391	$ (63)	$ 2,598,114	$ (195,915)	$ (5,067)
Ending balance (in shares) at Dec. 31, 2021		76,990,066	180,316