Condensed Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2023	Mar. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, no par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	12,658,000	12,658,000
Common stock, shares outstanding	7,289,000	7,289,000
Treasury Stock, Common, Shares	5,368,000	5,368,000