Document and Entity Information (USD $)	12 Months Ended
	Apr. 30, 2014	Jul. 04, 2014	Jul. 05, 2013
Document and Entity Information [Abstract]
Entity Registrant Name	BUTLER NATIONAL CORP
Entity Central Index Key	0000015847
Current Fiscal Year End Date	--04-30
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Public Float		$ 7,474,379
Entity Common Stock, Shares Outstanding			61,493,092
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Apr. 30, 2014