Segment Reporting and Sales by Major Customer - Professional Services (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2025	Oct. 31, 2024	Oct. 31, 2025	Oct. 31, 2024
Segment Reporting Information [Line Items]
Revenues from customers	$ 23,251	$ 21,360	$ 43,376	$ 41,189
Interest expense	501	538	1,025	1,103
Depreciation and amortization	1,691	1,658	3,394	3,254
Operating Income (Loss)	7,077	4,854	11,744	8,390
Gaming
Segment Reporting Information [Line Items]
Revenues from customers	9,212	9,650	18,023	18,887
Interest expense	395	458	810	949
Depreciation and amortization	749	808	1,523	1,600
Operating Income (Loss)	1,676	3,096	3,458	5,850
Aircraft Modification
Segment Reporting Information [Line Items]
Revenues from customers	8,414	7,170	14,056	14,276
Interest expense	98	66	196	125
Depreciation and amortization	891	789	1,768	1,533
Operating Income (Loss)	1,703	1,191	2,417	1,746
Aircraft Avionics
Segment Reporting Information [Line Items]
Revenues from customers	852	824	2,289	1,285
Interest expense	0	0	0	0
Depreciation and amortization	7	7	14	13
Operating Income (Loss)	657	(24)	1,155	10
Special Mission Electronics
Segment Reporting Information [Line Items]
Revenues from customers	4,773	3,716	9,008	6,741
Interest expense	8	14	19	28
Depreciation and amortization	27	34	57	68
Operating Income (Loss)	2,665	1,903	4,622	3,287
Other
Segment Reporting Information [Line Items]
Revenues from customers	0	0	0	0
Interest expense	0	0	0	1
Depreciation and amortization	17	20	32	40
Operating Income (Loss)	$ 376	$ (1,312)	$ 92	$ (2,503)