STOCKHOLDERS' EQUITY AND INCENTIVE PLANS - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended				12 Months Ended
	Mar. 17, 2020	Apr. 12, 2019	Apr. 30, 2025	Mar. 31, 2025	Jan. 31, 2025	Oct. 31, 2023	Apr. 30, 2025	Apr. 30, 2024	Nov. 30, 2016
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock award to director							$ 62	$ 222
Share-based payment arrangement, expense							$ 381	634
Shares issued, value, share-based payment arrangement, forfeited								427
Share-based payment arrangement, expense, tax benefit								$ 207
Butler National Corporation 2016 Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized (in shares)									12,500,000
Stock issued during period, value, restricted stock award, gross	$ 2,000
Butler National Corporation 2016 Equity Incentive Plan | Director
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period (year)					2 years
Stock award to director (in shares)				39,430	87,000	300,000
Shares issued, price per share (in dollars per share)				$ 1.59	$ 1.73	$ 0.74
Stock award to director				$ 63	$ 150	$ 222
Butler National Corporation 2016 Equity Incentive Plan | Restricted Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period (in shares)	5,000,000.0	2,500,000
Share-based compensation arrangement by share-based payment award, equity instruments other than options, vested in period (in shares)			1,650,000
Share-based compensation arrangement by share-based payment award, equity instruments other than options, forfeited in period (in shares)			850,000				0	1,525,000
Share price (in dollars per share)	$ 0.41
Share-based compensation arrangement by share-based payment award, award vesting period (year)		5 years
Share-based payment arrangement, nonvested award, cost not yet recognized, amount			$ 100				$ 100
Butler National Corporation 2016 Equity Incentive Plan | Restricted Stock | Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition (year)							2 years