Convertible Preferred Stock and Common Stock Warrants (Schedule of stock by class) (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Class of Stock [Line Items]
Preferred stock, shares authorized	50,000,000	50,000,000
Shares outstanding	3,351,000	3,351,000
Series A Preferred [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized	2,000,000
Shares outstanding	1,992,000
Liquidation value/preference	$ 4,980,000
Series B Preferred [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized	1,800,000
Shares outstanding	1,359,000
Liquidation value/preference	$ 3,397,500