Stock-Based Compensation - Stock incentive plan and other information (Details) - USD ($)			3 Months Ended		6 Months Ended
	Sep. 05, 2019	Nov. 02, 2010	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 17, 2020	Mar. 20, 2007
Stock-Based Compensation
Share-based payment award, options, grants in period, gross			0	0	0	0
Unrecognized stock-based compensation expense			$ 673,000		$ 673,000
General and administrative expenses | Employees
Stock-Based Compensation
Allocated share-based compensation expense			73,000	$ 39,000	126,000	$ 78,000
Research and Development Expenses | Employees
Stock-Based Compensation
Allocated share-based compensation expense			29,000	21,000	58,000	41,000
Consultant | General and administrative expenses
Stock-Based Compensation
Allocated share-based compensation expense			33,000	46,000	66,000	93,000
Consultant | Research and Development Expenses
Stock-Based Compensation
Allocated share-based compensation expense			$ 11,000	$ 7,000	$ 21,000	$ 14,000
2007 Stock Plan
Stock-Based Compensation
Share-based payment award, options, outstanding, number			86		86			7,143
Share-based payment award, options, issued, number			86		86
2010 Stock Plan
Stock-Based Compensation
Share-based payment award, options, outstanding, number		8,572	202,095		202,095
Share-based payment award, options, issued, number			202,095		202,095
Shares Available			0		0
Share-based compensation arrangement by share-based payment award, number of shares authorized	400,000
2010 Stock Plan | Minimum
Stock-Based Compensation
Share-based payment award, options, grants, expired period		5 years
2010 Stock Plan | Maximum
Stock-Based Compensation
Share-based payment award, options, grants, expired period		10 years
2020 Stock Plan
Stock-Based Compensation
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