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, 2025	Apr. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net income attributable to Butler National Corporation	$ 12,551	$ 12,512
Weighted average common shares outstanding (in shares)	67,819,328	70,435,752
Weighted average number of shares outstanding, diluted, adjustment (in shares)	16,249	0
Weighted average common shares outstanding, assuming dilution (in shares)	67,835,577	70,435,752
Potential common shares if all options were exercised and shares issued (in shares)	67,835,577	70,435,752
Basic earnings per common share (in dollars per share)	$ 0.19	$ 0.18
DILUTED EARNINGS PER COMMON SHARE ATTRIBUTABLE TO BUTLER NATIONAL CORPORATION (in dollars per share)	$ 0.19	$ 0.18