Document and Entity Information (USD $)	9 Months Ended
	Jan. 31, 2014	Mar. 07, 2014	Oct. 31, 2012
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			$ 12,426,554
Entity Common Stock, Shares Outstanding		59,619,173
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jan. 31, 2014