Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Gain (Loss)	Treasury Stock
Balance, shares at Dec. 31, 2021		150,082,000
Balance, value at Dec. 31, 2021	$ 113,595	$ 150	$ 1,608,749	$ (1,487,776)	$ (10)	$ (7,518)
Stock-based compensation	2,772		2,772
Repurchase of common stock	(864)					(864)
Issuance of equity-classified warrants	698		698
Issuance of treasury stock	0		(6,321)			6,321
Net loss	(23,476)			(23,476)
Unrealized gain (loss) on investments	(27)				(27)
Balance, shares at Mar. 31, 2022		150,082,000
Balance, value at Mar. 31, 2022	92,698	$ 150	1,605,898	(1,511,252)	(37)	(2,061)
Balance, shares at Dec. 31, 2021		150,082,000
Balance, value at Dec. 31, 2021	113,595	$ 150	1,608,749	(1,487,776)	(10)	(7,518)
Issuance of equity-classified warrants	698
Issuance of treasury stock	6,321
Net loss	(71,450)
Unrealized gain (loss) on investments	(481)
Balance, shares at Sep. 30, 2022		189,214,000
Balance, value at Sep. 30, 2022	144,018	$ 189	1,705,607	(1,559,226)	(491)	(2,061)
Balance, shares at Mar. 31, 2022		150,082,000
Balance, value at Mar. 31, 2022	92,698	$ 150	1,605,898	(1,511,252)	(37)	(2,061)
Stock-based compensation	2,832		2,832
Issuance of common stock under Equity Incentive Plans (in shares)		32,000
Net loss	(24,587)			(24,587)
Unrealized gain (loss) on investments	(113)				(113)
Balance, shares at Jun. 30, 2022		150,114,000
Balance, value at Jun. 30, 2022	70,830	$ 150	1,608,730	(1,535,839)	(150)	(2,061)
Stock-based compensation	2,648		2,648
Issuance of common stock, net of issuance fees (in shares)		39,100,000
Issuance of common stock, net of issuance fees	94,268	$ 39	94,229
Net loss	(23,387)			(23,387)
Unrealized gain (loss) on investments	(341)				(341)
Balance, shares at Sep. 30, 2022		189,214,000
Balance, value at Sep. 30, 2022	$ 144,018	$ 189	1,705,607	(1,559,226)	(491)	(2,061)
Balance, shares at Dec. 31, 2022	189,213,948	189,214,000
Balance, value at Dec. 31, 2022	$ 117,124	$ 189	1,709,144	(1,589,720)	(428)	(2,061)
Stock-based compensation	3,415		3,415
Issuance of common stock under Equity Incentive Plans (in shares)		1,216,000
Issuance of common stock under Equity Incentive Plans	0	$ 1	(1)
Repurchase of common stock	(824)					(824)
Net loss	(31,934)			(31,934)
Unrealized gain (loss) on investments	265				265
Balance, shares at Mar. 31, 2023		190,430,000
Balance, value at Mar. 31, 2023	$ 88,046	$ 190	1,712,558	(1,621,654)	(163)	(2,885)
Balance, shares at Dec. 31, 2022	189,213,948	189,214,000
Balance, value at Dec. 31, 2022	$ 117,124	$ 189	1,709,144	(1,589,720)	(428)	(2,061)
Issuance of equity-classified warrants	307
Issuance of treasury stock	0
Net loss	(127,363)
Unrealized gain (loss) on investments	$ 315
Balance, shares at Sep. 30, 2023	245,792,668	245,793,000
Balance, value at Sep. 30, 2023	$ 139,510	$ 245	1,859,346	(1,717,083)	(113)	(2,885)
Balance, shares at Mar. 31, 2023		190,430,000
Balance, value at Mar. 31, 2023	88,046	$ 190	1,712,558	(1,621,654)	(163)	(2,885)
Stock-based compensation	3,815		3,815
Issuance of common stock under Equity Incentive Plans (in shares)		75,000
Issuance of equity-classified warrants	307		307
Issuance of common stock, net of issuance fees (in shares)		55,288,000
Issuance of common stock, net of issuance fees	139,034	$ 55	138,979
Net loss	(44,904)			(44,904)
Unrealized gain (loss) on investments	63				63
Balance, shares at Jun. 30, 2023		245,793,000
Balance, value at Jun. 30, 2023	186,361	$ 245	1,855,659	(1,666,558)	(100)	(2,885)
Stock-based compensation	3,898		3,898
Net loss	(50,525)			(50,525)
Unrealized gain (loss) on investments	(13)				(13)
Other	$ (211)		(211)
Balance, shares at Sep. 30, 2023	245,792,668	245,793,000
Balance, value at Sep. 30, 2023	$ 139,510	$ 245	$ 1,859,346	$ (1,717,083)	$ (113)	$ (2,885)