Note 1 - Nature of Operations, Organization and Significant Accounting Policies - Computation of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Net income attributable to Butler National Corporation	$ 4,516	$ 10,368
Weighted average common shares outstanding (in shares)	76,456,631	75,340,131
Dilutive effect of non-qualified stock option plans (in shares)	0	0
Weighted average common shares outstanding, assuming dilution (in shares)	76,456,631	75,340,131
Potential common shares if all options were exercised and shares issued (in shares)	76,456,631	75,340,131
Basic earnings per common share (in dollars per share)	$ 0.06	$ 0.14
Diluted earnings per common share (in dollars per share)	$ 0.06	$ 0.14