Note 2 - Disaggregation of Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2024	Apr. 30, 2023
Revenues	$ 78,376	$ 75,182
Percentage of Completion Contracts [Member]
Revenues	22,570	22,500
Transferred at Point in Time [Member]
Revenues	55,806	52,682
Casino [Member]
Revenues	29,441	30,564
Sportsbook [Member]
Revenues	4,585	2,738
Casino Non-gaming [Member]
Revenues	4,551	4,456
Professional Services [Member]
Revenues	63	283
Aircraft Modification [Member]
Revenues	25,061	24,016
Aircraft Avionics [Member]
Revenues	2,722	2,324
Special Mission Electronics [Member]
Revenues	11,953	10,801
Professional Services [Member]
Revenues	38,640	38,041
Professional Services [Member] | Percentage of Completion Contracts [Member]
Revenues	0	0
Professional Services [Member] | Transferred at Point in Time [Member]
Revenues	38,640	38,041
Professional Services [Member] | Casino [Member]
Revenues	29,441	30,564
Professional Services [Member] | Sportsbook [Member]
Revenues	4,585	2,738
Professional Services [Member] | Casino Non-gaming [Member]
Revenues	4,551	4,456
Professional Services [Member] | Professional Services [Member]
Revenues	63	283
Professional Services [Member] | Aircraft Modification [Member]
Revenues	0	0
Professional Services [Member] | Aircraft Avionics [Member]
Revenues	0	0
Professional Services [Member] | Special Mission Electronics [Member]
Revenues	0	0
Aerospace Products [Member]
Revenues	39,736	37,141
Aerospace Products [Member] | Percentage of Completion Contracts [Member]
Revenues	22,570	22,500
Aerospace Products [Member] | Transferred at Point in Time [Member]
Revenues	17,166	14,641
Aerospace Products [Member] | Casino [Member]
Revenues	0	0
Aerospace Products [Member] | Sportsbook [Member]
Revenues	0	0
Aerospace Products [Member] | Casino Non-gaming [Member]
Revenues	0	0
Aerospace Products [Member] | Professional Services [Member]
Revenues	0	0
Aerospace Products [Member] | Aircraft Modification [Member]
Revenues	25,061	24,016
Aerospace Products [Member] | Aircraft Avionics [Member]
Revenues	2,722	2,324
Aerospace Products [Member] | Special Mission Electronics [Member]
Revenues	11,953	10,801
North America [Member]
Revenues	65,069	68,544
North America [Member] | Professional Services [Member]
Revenues	38,640	38,041
North America [Member] | Aerospace Products [Member]
Revenues	26,429	30,503
Europe [Member]
Revenues	8,161	1,095
Europe [Member] | Professional Services [Member]
Revenues	0	0
Europe [Member] | Aerospace Products [Member]
Revenues	8,161	1,095
Middle East [Member]
Revenues	1,606	4,614
Middle East [Member] | Professional Services [Member]
Revenues	0	0
Middle East [Member] | Aerospace Products [Member]
Revenues	1,606	4,614
Asia [Member]
Revenues	3,540	929
Asia [Member] | Professional Services [Member]
Revenues	0	0
Asia [Member] | Aerospace Products [Member]
Revenues	$ 3,540	$ 929