Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020
REVENUE:
Revenues from customers	$ 19,093	$ 15,972	$ 37,237	$ 28,961
COSTS AND EXPENSES:
Marketing and advertising	1,267	893	2,471	1,845
Employee benefits	546	566	1,121	1,151
Depreciation and amortization	705	1,075	1,407	2,118
General, administrative and other	2,028	1,646	3,956	3,416
Total costs and expenses	14,350	14,285	28,472	27,146
OPERATING INCOME	4,743	1,687	8,765	1,815
OTHER INCOME (EXPENSE):
Interest expense	(640)	(1,065)	(1,254)	(1,653)
Gain on sale of airplane	75	0	75	0
Total other income (expense)	(565)	(1,065)	822	(1,653)
INCOME BEFORE INCOME TAXES	4,178	622	9,587	162
Forgiveness of debt			2,001	0
PROVISION FOR INCOME TAXES
Provision for income taxes	794	120	1,425	114
Deferred income tax	234	0	234	0
NET INCOME	3,150	502	7,928	48
Net income attributable to former noncontrolling interest in BHCMC, LLC	0	(181)	(1,872)	258
NET INCOME ATTRIBUTABLE TO BUTLER NATIONAL CORPORATION	$ 3,150	$ 321	$ 6,056	$ 306
BASIC EARNINGS PER COMMON SHARE (in dollars per share)	$ 0.04	$ 0.00	$ 0.08	$ 0.00
WEIGHTED AVERAGE SHARES USED IN PER SHARE CALCULATION (in shares)	75,364,083	74,130,934	75,365,416	74,258,559
DILUTED EARNINGS PER COMMON SHARE (in dollars per share)	$ 0.04	$ 0.00	$ 0.08	$ 0.00
WEIGHTED AVERAGE SHARES USED IN PER SHARE CALCULATION (in shares)	75,364,083	74,130,934	75,365,416	74,258,559
Professional Services [Member]
REVENUE:
Revenues from customers	$ 9,676	$ 7,648	$ 19,401	$ 13,001
COSTS AND EXPENSES:
Cost of services and products	3,877	3,418	7,578	6,828
Aerospace Products [Member]
REVENUE:
Revenues from customers	9,417	8,324	17,836	15,960
COSTS AND EXPENSES:
Cost of services and products	$ 5,927	$ 6,687	$ 11,939	$ 11,788