Note 15 - Segment Reporting and Sales by Major Customer - Professional Services (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2023	Jul. 31, 2022
Revenues from customers	$ 17,185	$ 15,304
Interest expense	639	723
Depreciation and amortization	1,423	1,458
Operating income (loss)	1,137	1,625
Gaming [Member]
Revenues from customers	8,989	8,893
Interest expense	556	642
Depreciation and amortization	648	626
Operating income (loss)	2,314	2,642
Aircraft Modification [Member]
Revenues from customers	5,483	3,836
Interest expense	58	66
Depreciation and amortization	713	740
Operating income (loss)	(793)	54
Aircraft Avionics [Member]
Revenues from customers	744	715
Interest expense	0	0
Depreciation and amortization	3	2
Operating income (loss)	(86)	48
Special Mission Electronics [Member]
Revenues from customers	1,917	1,791
Interest expense	16	7
Depreciation and amortization	32	39
Operating income (loss)	721	616
Product and Service, Other [Member]
Revenues from customers	52	69
Interest expense	9	8
Depreciation and amortization	27	51
Operating income (loss)	$ (1,019)	$ (1,735)