Note 11 - Stock Options and Incentive Plans (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	3 Months Ended	9 Months Ended
	Mar. 17, 2020	Apr. 12, 2019	Jul. 31, 2022	Jul. 31, 2022	Jan. 31, 2023	Jan. 31, 2022	Nov. 30, 2016
Stock Issued During Period, Value, Issued for Services				$ 352
Share-Based Payment Arrangement, Expense					$ 585	$ 437
Butler National Corporation 2016 Equity Incentive Plan [Member]
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	$ 950
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)				0
Butler National Corporation 2016 Equity Incentive Plan [Member] | Director [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)			400,000
Shares Issued, Price Per Share (in dollars per share)			$ 0.88	$ 0.88
Stock Issued During Period, Value, Issued for Services			$ 352
Butler National Corporation 2016 Equity Incentive Plan [Member] | Restricted Stock [Member]
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 Price (in dollars per share)	$ 0.41	$ 0.38
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)		5 years