Document And Entity Information - USD ($)	12 Months Ended
	Apr. 30, 2023	Jul. 31, 2023	Oct. 31, 2022
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	FY
Document Fiscal Year Focus	2023
Document Type	10-K
Document Annual Report	true
Document Period End Date	Apr. 30, 2023
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
Title of 12(b) Security	Common Stock $.01 Par Value
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 39,075,606
Entity Common Stock, Shares Outstanding		68,727,900
No Trading Symbol Flag	true
Auditor Name	RBSM LLP
Auditor Location	Las Vegas, NV
Auditor Firm ID	87