Statements of Changes in Stockholders' Deficit - USD ($)	Preferred Stock Series B Convertible Preferred Stock	Preferred Stock Series A and B Convertible Preferred Stock	Preferred Stock	Common stock Public offering	Common stock At-the-market sales	Common stock Series A Convertible Preferred Stock	Common stock Series B Convertible Preferred Stock	Common stock	Additional Paid-in Capital. At-the-market sales	Additional Paid-in Capital.	Accumulated Deficit	At-the-market sales	Total
Balance at Dec. 31, 2021										$ 387,205,000	$ (383,290,000)		$ 3,915,000
Balance (in shares) at Dec. 31, 2021								60,698,000
Increase (decrease) in stockholders' equity
Share-based compensation - stock options and RSUs										764,000			764,000
Issuance of common stock									$ 348,000			$ 348,000
Issuance of common stock (in shares)					512,000
Issuance of common stock upon exercise of options (in shares)		4,850
Conversion of convertible preferred stock (in shares)						6,063,000
Vesting of RSUs			$ (2,425)
Vesting of RSUs (in shares)								35,000
Net loss											(10,385,000)		(10,385,000)
Balance at Mar. 31, 2022										388,317,000	(393,675,000)		(5,358,000)
Balance (in shares) at Mar. 31, 2022			2,425					67,308,000
Balance at Dec. 31, 2021										387,205,000	(383,290,000)		3,915,000
Balance (in shares) at Dec. 31, 2021								60,698,000
Increase (decrease) in stockholders' equity
Net loss													(15,553,000)
Balance at Jun. 30, 2022										401,212,000	(398,843,000)		2,369,000
Balance (in shares) at Jun. 30, 2022								247,202,000
Balance at Dec. 31, 2021										387,205,000	(383,290,000)		3,915,000
Balance (in shares) at Dec. 31, 2021								60,698,000
Balance at Dec. 31, 2022										403,157,000	(408,702,000)		(5,545,000)
Balance (in shares) at Dec. 31, 2022								859,402
Balance at Mar. 31, 2022										388,317,000	(393,675,000)		(5,358,000)
Balance (in shares) at Mar. 31, 2022			2,425					67,308,000
Increase (decrease) in stockholders' equity
Share-based compensation - stock options and RSUs										669,000			669,000
Issuance of common stock									12,226,000			12,226,000
Issuance of common stock (in shares)					173,750,000
Conversion of convertible preferred stock (in shares)	(2,425)						6,062,000
Vesting of RSUs (in shares)								82,000
Net loss											(5,168,000)		(5,168,000)
Balance at Jun. 30, 2022										401,212,000	(398,843,000)		2,369,000
Balance (in shares) at Jun. 30, 2022								247,202,000
Balance at Dec. 31, 2022										403,157,000	(408,702,000)		(5,545,000)
Balance (in shares) at Dec. 31, 2022								859,402
Increase (decrease) in stockholders' equity
Share-based compensation - stock options and RSUs										498,000			498,000
Issuance of common stock									1,003,000			1,003,000
Issuance of common stock (in shares)					72,699
Net loss											(5,389,000)		(5,389,000)
Balance at Mar. 31, 2023										404,658,000	(414,091,000)		(9,433,000)
Balance (in shares) at Mar. 31, 2023								932,101
Balance at Dec. 31, 2022										403,157,000	(408,702,000)		(5,545,000)
Balance (in shares) at Dec. 31, 2022								859,402
Increase (decrease) in stockholders' equity
Net loss													(9,197,000)
Balance at Jun. 30, 2023										405,779,000	(417,900,000)		(12,121,000)
Balance (in shares) at Jun. 30, 2023								1,640,805
Balance at Mar. 31, 2023										404,658,000	(414,091,000)		(9,433,000)
Balance (in shares) at Mar. 31, 2023								932,101
Increase (decrease) in stockholders' equity
Share-based compensation - stock options and RSUs										$ 482,000			$ 482,000
Fractional shares retired as a result of reverse split										13,000			13,000
Issuance of common stock									$ 652,000			$ 652,000
Issuance of common stock (in shares)				95,000	105,342
Exercise of pre-funded warrants (in shares)								508,286
Vesting of RSUs (in shares)								76
Net loss											(3,809,000)		$ (3,809,000)
Balance at Jun. 30, 2023										$ 405,779,000	$ (417,900,000)		$ (12,121,000)
Balance (in shares) at Jun. 30, 2023								1,640,805