Stock-Based Compensation - Stock incentive plan and other information (Details) - USD ($)			3 Months Ended		9 Months Ended
	Sep. 05, 2019	Nov. 02, 2010	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 17, 2020	Mar. 20, 2007
Organization, Nature of Operations and Basis of Presentation
Share-based payment award, options, grants in period, gross			0	3,000	0	3,000
Unrecognized stock-based compensation expense			$ 539,000		$ 539,000
General and administrative expenses | Employees
Organization, Nature of Operations and Basis of Presentation
Allocated share-based compensation expense			61,000	$ 46,000	187,000	$ 124,000
Research and Development Expenses | Employees
Organization, Nature of Operations and Basis of Presentation
Allocated share-based compensation expense			29,000	21,000	87,000	62,000
Consultant | General and administrative expenses
Organization, Nature of Operations and Basis of Presentation
Allocated share-based compensation expense			34,000	47,000	101,000	141,000
Consultant | Research and Development Expenses
Organization, Nature of Operations and Basis of Presentation
Allocated share-based compensation expense			$ 11,000	$ 7,000	$ 32,000	$ 21,000
2007 Stock Plan
Organization, Nature of Operations and Basis of Presentation
Share-based payment award, options, outstanding, number			86		86			7,143
Share-based payment award, options, issued, number			86		86
2010 Stock Plan
Organization, Nature of Operations and Basis of Presentation
Share-based payment award, options, outstanding, number		8,572	202,095		202,095
Share-based payment award, options, issued, number			202,095		202,095
Share-based compensation arrangement by share-based payment award, number of shares authorized	400,000
Shares available			0		0
2010 Stock Plan | Minimum
Organization, Nature of Operations and Basis of Presentation
Share-based payment award, options, grants, expired period		5 years
2010 Stock Plan | Maximum
Organization, Nature of Operations and Basis of Presentation
Share-based payment award, options, grants, expired period		10 years
2020 Stock Plan
Organization, Nature of Operations and Basis of Presentation
Share-based payment award, options, outstanding, number			2,082,155		2,082,155		400,000
Share-based payment award, options, issued, number			2,082,155		2,082,155
Share-based compensation arrangement by share-based payment award, number of shares authorized					7,000,000