Note 16 - Segment Reporting and Sales by Major Customer - Professional Services (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2024	Oct. 31, 2023	Oct. 31, 2024	Oct. 31, 2023
Revenues from customers	$ 21,360	$ 19,602	$ 41,189	$ 36,786
Interest expense	538	615	1,103	1,254
Depreciation and amortization	1,658	1,626	3,254	3,049
Operating income (loss)	4,854	3,598	8,390	4,735
Gaming [Member]
Revenues from customers	9,650	9,770	18,887	18,758
Interest expense	458	532	949	1,088
Depreciation and amortization	808	830	1,600	1,478
Operating income (loss)	3,096	2,767	5,850	5,081
Aircraft Modification [Member]
Revenues from customers	7,170	6,082	14,276	11,565
Interest expense	66	58	125	116
Depreciation and amortization	789	726	1,533	1,439
Operating income (loss)	1,191	557	1,746	(191)
Aircraft Avionics [Member]
Revenues from customers	824	778	1,285	1,522
Interest expense	0	0	0	0
Depreciation and amortization	7	4	13	7
Operating income (loss)	(24)	(105)	10	(146)
Special Mission Electronics [Member]
Revenues from customers	3,716	2,972	6,741	4,889
Interest expense	14	16	28	33
Depreciation and amortization	34	31	68	63
Operating income (loss)	1,903	1,482	3,287	2,203
Product and Service, Other [Member]
Revenues from customers	0	0	0	52
Interest expense	0	9	1	17
Depreciation and amortization	20	35	40	62
Operating income (loss)	$ (1,312)	$ (1,103)	$ (2,503)	$ (2,212)