CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Preferred Stock Series A Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Total
Balance at Dec. 31, 2021		$ 2,204	$ 1,794,525	$ (1,471,143)	$ 325,586
Balance (in shares) at Dec. 31, 2021		220,361
Increase (Decrease) in Shareholders' Equity (Deficit)
Net loss				(24,145)	(24,145)
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan		$ 1	619		620
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan (in shares)		173
Restricted stock units vested (in shares)		2
Stock option and restricted stock compensation expense			4,196		4,196
Directors' deferred share unit compensation			211		211
Balance at Mar. 31, 2022		$ 2,205	1,799,551	(1,495,288)	306,468
Balance (in shares) at Mar. 31, 2022		220,536
Balance at Dec. 31, 2021		$ 2,204	1,794,525	(1,471,143)	325,586
Balance (in shares) at Dec. 31, 2021		220,361
Increase (Decrease) in Shareholders' Equity (Deficit)
Net loss					(163,921)
Balance at Sep. 30, 2022		$ 2,208	1,810,863	(1,635,064)	178,007
Balance (in shares) at Sep. 30, 2022		220,751
Balance at Mar. 31, 2022		$ 2,205	1,799,551	(1,495,288)	306,468
Balance (in shares) at Mar. 31, 2022		220,536
Increase (Decrease) in Shareholders' Equity (Deficit)
Net loss				(62,021)	(62,021)
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan		$ 1	410		411
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan (in shares)		108
Stock option and restricted stock compensation expense			4,760		4,760
Directors' deferred share unit compensation			213		213
Balance at Jun. 30, 2022		$ 2,206	1,804,934	(1,557,309)	249,831
Balance (in shares) at Jun. 30, 2022		220,644
Increase (Decrease) in Shareholders' Equity (Deficit)
Net loss				(77,755)	(77,755)
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan		$ 2	447		449
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan (in shares)		107
Stock option and restricted stock compensation expense			5,336		5,336
Directors' deferred share unit compensation			146		146
Balance at Sep. 30, 2022		$ 2,208	1,810,863	(1,635,064)	178,007
Balance (in shares) at Sep. 30, 2022		220,751
Increase (Decrease) in Shareholders' Equity (Deficit)
Net loss				(59,008)	(59,008)
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan		$ 1	423		424
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan (in shares)		103
Issuance of common stock, net of issuance costs		$ 51	25,596		25,647
Issuance of common stock, net of issuance costs (in shares)		5,167
Restricted stock units vested (in shares)		25
Stock option and restricted stock compensation expense			10,610		10,610
Directors' deferred share unit compensation			146		146
Balance at Dec. 31, 2022		$ 2,260	1,847,638	(1,694,072)	$ 155,826
Balance (in shares) at Dec. 31, 2022		226,046			226,046
Increase (Decrease) in Shareholders' Equity (Deficit)
Issuance of Series A Preferred Stock in exchange for common stock
Issuance of Series A Preferred Stock in exchange for common stock (in shares)					0
Net loss				(41,014)	$ (41,014)
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan		$ 1	38		39
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan (in shares)		16
Stock option and restricted stock compensation expense			6,916		6,916
Directors' deferred share unit compensation			151		151
Directors' common stock compensation		8
Balance at Mar. 31, 2023		$ 2,261	1,854,743	(1,735,086)	121,918
Balance (in shares) at Mar. 31, 2023		226,070
Balance at Dec. 31, 2022		$ 2,260	1,847,638	(1,694,072)	$ 155,826
Balance (in shares) at Dec. 31, 2022		226,046			226,046
Increase (Decrease) in Shareholders' Equity (Deficit)
Net loss					$ (14,514)
Balance at Sep. 30, 2023	$ 22	$ 2,435	2,267,747	(1,708,586)	$ 561,596
Balance (in shares) at Sep. 30, 2023		265,842			265,842
Balance at Mar. 31, 2023		$ 2,261	1,854,743	(1,735,086)	$ 121,918
Balance (in shares) at Mar. 31, 2023		226,070
Increase (Decrease) in Shareholders' Equity (Deficit)
Net loss				(4,248)	(4,248)
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan		$ 32	14,874		14,906
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan (in shares)		3,234
Issuance of common stock, net of issuance costs		$ 299	350,534		350,833
Issuance of common stock, net of issuance costs (in shares)		29,900
Issuance of common stock pursuant to pre-funded warrant exchange		11,357
Issuance of Series A Preferred Stock in exchange for common stock (common stock)		(21,853)
Stock option and restricted stock compensation expense			7,281		7,281
Directors' deferred share unit compensation			152		152
Directors' common stock compensation		4
Balance at Jun. 30, 2023	$ 22	$ 2,374	2,227,802	(1,739,334)	490,842
Balance (in shares) at Jun. 30, 2023		248,712
Increase (Decrease) in Shareholders' Equity (Deficit)
Issuance of Series A Preferred Stock in exchange for common stock		$ (218)	218
Issuance of Series A Preferred Stock in exchange for common stock (in shares)	22
Net loss				30,748	30,748
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan		$ 61	32,105		32,166
Issuance of common stock pursuant to the exercise of stock options and employee stock purchase plan (in shares)		6,136
Issuance of common stock, net of issuance costs			(34)		(34)
Issuance of common stock pursuant to pre-funded warrant exchange		10,992
Stock option and restricted stock compensation expense			7,807		7,807
Directors' deferred share unit compensation			67		67
Directors' common stock compensation		2
Balance at Sep. 30, 2023	$ 22	$ 2,435	$ 2,267,747	$ (1,708,586)	$ 561,596
Balance (in shares) at Sep. 30, 2023		265,842			265,842
Increase (Decrease) in Shareholders' Equity (Deficit)
Issuance of Series A Preferred Stock in exchange for common stock
Issuance of Series A Preferred Stock in exchange for common stock (in shares)					22