Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Jan. 31, 2025	Apr. 30, 2024
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	50,000,000	50,000,000
Common stock, issued (in shares)	15,599,303	13,727,013
Common stock, outstanding (in shares)	8,256,765	6,394,675
Treasury stock, at cost (in shares)	7,342,538	7,332,338