Note 4 - Disaggregation of Revenue - Disaggregation of Revenue (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
Percentage of Completion Contracts [Member]
Revenues from customers	6,539	5,401	12,619	10,613
Transferred at Point in Time [Member]
Revenues from customers	14,821	14,201	28,570	26,173
Casino [Member]
Revenues from customers	7,016	7,298	14,098	14,496
Sportsbook [Member]
Revenues from customers	1,436	1,314	2,443	2,015
Casino Non-gaming [Member]
Revenues from customers	1,198	1,158	2,346	2,247
Professional Services [Member]
Revenues from customers	0	0	0	52
Aircraft Modification [Member]
Revenues from customers	7,170	6,082	14,276	11,565
Aircraft Avionics [Member]
Revenues from customers	824	778	1,285	1,522
Special Mission Electronics [Member]
Revenues from customers	3,716	2,972	6,741	4,889
Professional Services [Member]
Revenues from customers	9,650	9,770	18,887	18,810
Professional Services [Member] | Percentage of Completion Contracts [Member]
Revenues from customers	0	0	0	0
Professional Services [Member] | Transferred at Point in Time [Member]
Revenues from customers	9,650	9,770	18,887	18,810
Professional Services [Member] | Casino [Member]
Revenues from customers	7,016	7,298	14,098	14,496
Professional Services [Member] | Sportsbook [Member]
Revenues from customers	1,436	1,314	2,443	2,015
Professional Services [Member] | Casino Non-gaming [Member]
Revenues from customers	1,198	1,158	2,346	2,247
Professional Services [Member] | Professional Services [Member]
Revenues from customers	0	0	0	52
Professional Services [Member] | Aircraft Modification [Member]
Revenues from customers	0	0	0	0
Professional Services [Member] | Aircraft Avionics [Member]
Revenues from customers	0	0	0	0
Professional Services [Member] | Special Mission Electronics [Member]
Revenues from customers	0	0	0	0
Aerospace Products [Member]
Revenues from customers	11,710	9,832	22,302	17,976
Aerospace Products [Member] | Percentage of Completion Contracts [Member]
Revenues from customers	6,539	5,401	12,619	10,613
Aerospace Products [Member] | Transferred at Point in Time [Member]
Revenues from customers	5,171	4,431	9,683	7,363
Aerospace Products [Member] | Casino [Member]
Revenues from customers	0	0	0	0
Aerospace Products [Member] | Sportsbook [Member]
Revenues from customers	0	0	0	0
Aerospace Products [Member] | Casino Non-gaming [Member]
Revenues from customers	0	0	0	0
Aerospace Products [Member] | Professional Services [Member]
Revenues from customers	0	0	0	0
Aerospace Products [Member] | Aircraft Modification [Member]
Revenues from customers	7,170	6,082	14,276	11,565
Aerospace Products [Member] | Aircraft Avionics [Member]
Revenues from customers	824	778	1,285	1,522
Aerospace Products [Member] | Special Mission Electronics [Member]
Revenues from customers	3,716	2,972	6,741	4,889
North America [Member]
Revenues from customers	17,709	18,409	33,313	32,994
North America [Member] | Professional Services [Member]
Revenues from customers	9,650	9,770	18,887	18,810
North America [Member] | Aerospace Products [Member]
Revenues from customers	8,059	8,639	14,426	14,184
Europe [Member]
Revenues from customers	3,108	952	6,643	1,619
Europe [Member] | Professional Services [Member]
Revenues from customers	0	0	0	0
Europe [Member] | Aerospace Products [Member]
Revenues from customers	3,108	952	6,643	1,619
Asia [Member]
Revenues from customers	473	4	928	358
Asia [Member] | Professional Services [Member]
Revenues from customers	0	0	0	0
Asia [Member] | Aerospace Products [Member]
Revenues from customers	473	4	928	358
Australia and Other [Member]
Revenues from customers	70	237	305	1,815
Australia and Other [Member] | Professional Services [Member]
Revenues from customers	0	0	0	0
Australia and Other [Member] | Aerospace Products [Member]
Revenues from customers	$ 70	$ 237	$ 305	$ 1,815