CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Common Stock owed but Not issued [Member]	Capital Contributed in Excess of Par [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Total Stockholders Equity Butler National Corporation [Member]	Noncontrolling Interest in BHCMC, LLC [Member]
BALANCE at Apr. 30, 2010	$ 16,308	$ 566	$ 3	$ 11,458	$ (732)	$ 5,012	$ 16,307	$ 1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock for services and other	78	2	0	76	0	0	78	0
Stock options issued to employees and directors	167	0	0	167	0	0	167	0
Issuance of stock benefit plan	214	4	0	210	0	0	214	0
Net income	1,258	0	0	0	0	1,259	1,259	(1)
BALANCE at Apr. 30, 2011	18,025	572	3	11,911	(732)	6,271	18,025	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options issued to employees and directors	384	0	0	384	0	0	384	0
Contributed capital	1	0	0	0	0	0	0	1
Issuance of stock benefit plan	278	7	0	271	0	0	278	0
Net income	3,916	0	0	0	0	1,899	1,899	2,016
BALANCE at Apr. 30, 2012	22,604	579	3	12,567	(732)	8,170	20,587	2,017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock for services and other	90	2	(3)	91	0	0	90	0
Stock options issued to employees and directors	110	0	0	110	0	0	110	0
BHCMC distribution noncontrolling member	(320)	0	0	0	0			(320)
Issuance of stock benefit plan	281	15	0	266	0	0	281	0
Net income	809	0	0	0	0	(148)	(148)	957
BALANCE at Apr. 30, 2013	$ 23,574	$ 596	$ 0	$ 13,034	$ (732)	$ 8,022	$ 20,920	$ 2,654