Stock-Based Compensation - Stock incentive plan and other information (Details) - USD ($)			3 Months Ended		12 Months Ended
	Sep. 05, 2019	Nov. 02, 2010	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2022	Oct. 31, 2023	Sep. 17, 2020	Mar. 20, 2007
Stock-Based Compensation and Warrants
Share-based payment award, options, grants in period, gross			0	0
Unrecognized stock-based compensation expense			$ 1,100,000
Class Of Warrant Or Right Outstanding						0
General and administrative expenses | Employees
Stock-Based Compensation and Warrants
Allocated share-based compensation expense			106,000	$ 83,000
Consultant | Research and Development Expenses
Stock-Based Compensation and Warrants
Allocated share-based compensation expense			$ 54,000	$ 43,000
2007 Stock Plan
Stock-Based Compensation and Warrants
Share-based payment award, options, outstanding, number			86					7,143
Share-based payment award, options, issued, number			86
2010 Stock Plan
Stock-Based Compensation and Warrants
Share-based payment award, options, outstanding, number		8,572	198,540
Share-based payment award, options, issued, number			198,540
Share-based compensation arrangement by share-based payment award, number of shares authorized	400,000
Shares available			0
2010 Stock Plan | Minimum
Stock-Based Compensation and Warrants
Share-based payment award, options, grants, expired period		5 years
2010 Stock Plan | Maximum
Stock-Based Compensation and Warrants
Share-based payment award, options, grants, expired period		10 years
2020 Stock Plan
Stock-Based Compensation and Warrants
Share-based payment award, options, outstanding, number			4,177,155				400,000
Share-based payment award, options, issued, number			4,177,155
Share-based compensation arrangement by share-based payment award, number of shares authorized					7,000,000