Document And Entity Information - shares	9 Months Ended
	Jan. 31, 2024	Mar. 15, 2024
Document Information [Line Items]
Entity Central Index Key	0000015847
Entity Registrant Name	BUTLER NATIONAL CORP
Amendment Flag	false
Current Fiscal Year End Date	--04-30
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2024
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jan. 31, 2024
Document Transition Report	false
Entity File Number	0-1678
Entity Incorporation, State or Country Code	KS
Entity Tax Identification Number	41-0834293
Entity Address, Address Line One	One Aero Plaza
Entity Address, City or Town	New Century
Entity Address, State or Province	KS
Entity Address, Postal Zip Code	66031
City Area Code	913
Local Phone Number	780-9595
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		68,850,856