Condensed Unaudited Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock	Common Stock	Additional paid-in capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at beginning of period (in shares) at Dec. 31, 2020		0	90,121
Beginning balance at Dec. 31, 2020	$ 191,563	$ 0	$ 90	$ 756,543	$ (565,073)	$ 3
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under employee stock compensation plans and warrants (in shares)			49
Issuance of common stock under employee stock compensation plans and warrants	129			129
Share-based compensation	2,292			2,292
Net loss	(26,795)				(26,795)
Unrealized loss on available for sale securities, net of tax	(1)					(1)
Balance at end of period (in shares) at Mar. 31, 2021		0	90,170
Ending balance at Mar. 31, 2021	167,188	$ 0	$ 90	758,964	(591,868)	2
Balance at beginning of period (in shares) at Dec. 31, 2020		0	90,121
Beginning balance at Dec. 31, 2020	191,563	$ 0	$ 90	756,543	(565,073)	3
Increase (Decrease) in Stockholders' Equity
Net loss	(81,489)
Balance at end of period (in shares) at Sep. 30, 2021		0	104,238
Ending balance at Sep. 30, 2021	226,486	$ 0	$ 104	872,955	(646,562)	(11)
Balance at beginning of period (in shares) at Mar. 31, 2021		0	90,170
Beginning balance at Mar. 31, 2021	167,188	$ 0	$ 90	758,964	(591,868)	2
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under employee stock compensation plans and warrants (in shares)			217
Issuance of common stock under employee stock compensation plans and warrants	448			448
Share-based compensation	2,079			2,079
Net loss	(30,143)				(30,143)
Unrealized loss on available for sale securities, net of tax	1					1
Balance at end of period (in shares) at Jun. 30, 2021		0	90,387
Ending balance at Jun. 30, 2021	139,573	$ 0	$ 90	761,491	(622,011)	3
Increase (Decrease) in Stockholders' Equity
Issuance of common stock and pre-funded warrants through underwritten offering, net of issuance costs (in shares)			13,398
Issuance of common stock and pre-funded warrants through underwritten offering, net of issuance costs	107,757		$ 14	107,743
Issuance of common stock under employee stock compensation plans and warrants (in shares)			453
Issuance of common stock under employee stock compensation plans and warrants	1,095			1,095
Share-based compensation	2,626			2,626
Net loss	(24,551)				(24,551)
Unrealized loss on available for sale securities, net of tax	(14)					(14)
Balance at end of period (in shares) at Sep. 30, 2021		0	104,238
Ending balance at Sep. 30, 2021	226,486	$ 0	$ 104	872,955	(646,562)	(11)
Balance at beginning of period (in shares) at Dec. 31, 2021		0	115,277
Beginning balance at Dec. 31, 2021	360,528	$ 0	$ 115	1,040,098	(679,595)	(90)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under employee stock compensation plans and warrants (in shares)			697
Issuance of common stock under employee stock compensation plans and warrants	2,080		$ 1	2,079
Share-based compensation	5,386			5,386
Net loss	(34,536)				(34,536)
Unrealized loss on available for sale securities, net of tax	(304)					(304)
Balance at end of period (in shares) at Mar. 31, 2022		0	115,974
Ending balance at Mar. 31, 2022	333,154	$ 0	$ 116	1,047,563	(714,131)	(394)
Balance at beginning of period (in shares) at Dec. 31, 2021		0	115,277
Beginning balance at Dec. 31, 2021	360,528	$ 0	$ 115	1,040,098	(679,595)	(90)
Increase (Decrease) in Stockholders' Equity
Net loss	(126,150)
Balance at end of period (in shares) at Sep. 30, 2022		0	120,572
Ending balance at Sep. 30, 2022	259,526	$ 0	$ 121	1,065,545	(805,745)	(395)
Balance at beginning of period (in shares) at Mar. 31, 2022		0	115,974
Beginning balance at Mar. 31, 2022	333,154	$ 0	$ 116	1,047,563	(714,131)	(394)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under employee stock compensation plans and warrants (in shares)			900
Issuance of common stock under employee stock compensation plans and warrants	2,801		$ 1	2,800
Share-based compensation	6,388			6,388
Net loss	(49,263)				(49,263)
Unrealized loss on available for sale securities, net of tax	(134)					(134)
Balance at end of period (in shares) at Jun. 30, 2022		0	116,874
Ending balance at Jun. 30, 2022	292,946	$ 0	$ 117	1,056,751	(763,394)	(528)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under employee stock compensation plans and warrants (in shares)			3,698
Issuance of common stock under employee stock compensation plans and warrants	2,242		$ 4	2,238
Share-based compensation	6,556			6,556
Net loss	(42,351)				(42,351)
Unrealized loss on available for sale securities, net of tax	133					133
Balance at end of period (in shares) at Sep. 30, 2022		0	120,572
Ending balance at Sep. 30, 2022	$ 259,526	$ 0	$ 121	$ 1,065,545	$ (805,745)	$ (395)