Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
REVENUES:
Revenues	$ 61,480	$ 65,871
COSTS AND EXPENSES:
Marketing and advertising	3,752	4,095
Employee benefits	2,571	2,606
Depreciation and amortization	3,542	4,165
General, administrative and other	8,208	8,298
Total costs and expenses	55,580	57,565
OPERATING INCOME	5,900	8,306
OTHER INCOME (EXPENSE):
Interest expense	(3,138)	(4,368)
Gain on sale of airplanes		642
Other	7
Total other income (expense)	(3,131)	(3,726)
INCOME BEFORE INCOME TAXES	2,769	4,580
PROVISION (BENEFIT) FOR INCOME TAXES
Provision for income taxes	536	1,594
Deferred income tax (benefit)	(225)	(260)
NET INCOME	2,458	3,246
Net (income) loss attributable to noncontrolling interest in BHCMC, LLC	(1,025)	988
NET INCOME ATTRIBUTABLE TO BUTLER NATIONAL CORPORATION	$ 1,433	$ 4,234
BASIC EARNINGS PER COMMON SHARE ATTRIBUTABLE TO BUTLER NATIONAL CORPORATION (in dollars per share)	$ 0.02	$ 0.06
WEIGHTED AVERAGE SHARES USED IN PER SHARE CALCULATION (in shares)	74,144,957	68,622,527
DILUTED EARNINGS PER COMMON SHARE ATTRIBUTABLE TO BUTLER NATIONAL CORPORATION (in dollars per share)	$ 0.02	$ 0.06
WEIGHTED AVERAGE SHARES USED IN PER SHARE CALCULATION (in shares)	74,144,957	68,622,527
Professional Services [Member]
REVENUES:
Revenues	$ 30,205	$ 28,283
COSTS AND EXPENSES:
Cost of services and products	14,214	15,516
Aerospace Products [Member]
REVENUES:
Revenues	31,275	37,588
COSTS AND EXPENSES:
Cost of services and products	$ 23,293	$ 22,885