Note 17 - Segment Reporting and Sales by Major Customer - Professional Services (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2025	Jan. 31, 2024
Revenues from customers	$ 21,174	$ 18,960	$ 62,363	$ 55,746
Interest expense	557	615	1,660	1,869
Depreciation and amortization	1,766	1,509	5,020	4,558
Operating income (loss)	4,026	3,795	12,416	8,531
Gaming [Member]
Revenues from customers	9,813	9,929	28,700	28,687
Interest expense	451	536	1,400	1,623
Depreciation and amortization	808	756	2,408	2,235
Operating income (loss)	3,234	3,059	9,084	8,139
Aircraft Modification [Member]
Revenues from customers	8,061	5,402	22,337	16,967
Interest expense	88	57	213	173
Depreciation and amortization	855	683	2,388	2,121
Operating income (loss)	773	546	2,519	267
Aircraft Avionics [Member]
Revenues from customers	915	810	2,200	2,332
Interest expense	0	0	0	0
Depreciation and amortization	7	7	20	13
Operating income (loss)	223	30	233	(26)
Special Mission Electronics [Member]
Revenues from customers	2,385	2,807	9,126	7,696
Interest expense	12	16	40	48
Depreciation and amortization	34	32	102	94
Operating income (loss)	883	1,375	4,170	3,578
Product and Service, Other [Member]
Revenues from customers	0	12	0	64
Interest expense	6	6	7	25
Depreciation and amortization	62	31	102	95
Operating income (loss)	$ (1,087)	$ (1,215)	$ (3,590)	$ (3,427)