Subsequent Events (Details) - USD ($) $ in Thousands		2 Months Ended	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Nov. 30, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Nov. 14, 2023	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Subsequent Events.
Net loss			$ (7,904)	$ (12,609)	$ (32,592)	$ (40,163)
Stockholders' equity			1,416	$ 3,599	1,416	$ 3,599		$ 5,830	$ (1,359)	$ 2,756	$ 11,853
Cash			$ 3,226		$ 3,226				$ 5,469
Subsequent event
Subsequent Events.
Estimated projected loss		$ (4,000)
Subsequent event | Series H convertible preferred stock
Subsequent Events.
Shares converted	48
Subsequent event | Series H convertible preferred stock
Subsequent Events.
Shares converted	32
Subsequent event | Series I convertible preferred stock
Subsequent Events.
Shares converted	62
Subsequent event | Common Stock | Series H convertible preferred stock
Subsequent Events.
Shares issued on conversion	2,400,000
Subsequent event | Common Stock | Series H convertible preferred stock
Subsequent Events.
Shares issued on conversion	1,600,000
Subsequent event | Common Stock | Series I convertible preferred stock
Subsequent Events.
Shares issued on conversion	2,985,362
Subsequent event | Minimum
Subsequent Events.
Stockholders' equity							$ 2,500
Cash							$ 6,000
Subsequent event | December 2021 ATM Agreement
Subsequent Events.
Number of shares issued		18,945,450
Total net proceeds		$ 7,000