Note 4 - Disaggregation of Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2024	Jul. 31, 2023
Revenues from customers	$ 19,828	$ 17,185
Percentage of Completion Contracts [Member]
Revenues from customers	6,080	5,213
Transferred at Point in Time [Member]
Revenues from customers	13,748	11,972
Casino [Member]
Revenues from customers	7,081	7,198
Sportsbook [Member]
Revenues from customers	1,007	701
Casino Non-gaming [Member]
Revenues from customers	1,148	1,090
Professional Services [Member]
Revenues from customers	0	52
Aircraft Modification [Member]
Revenues from customers	7,106	5,483
Aircraft Avionics [Member]
Revenues from customers	461	744
Special Mission Electronics [Member]
Revenues from customers	3,025	1,917
Professional Services [Member]
Revenues from customers	9,236	9,041
Professional Services [Member] | Percentage of Completion Contracts [Member]
Revenues from customers	0	0
Professional Services [Member] | Transferred at Point in Time [Member]
Revenues from customers	9,236	9,041
Professional Services [Member] | Casino [Member]
Revenues from customers	7,081	7,198
Professional Services [Member] | Sportsbook [Member]
Revenues from customers	1,007	701
Professional Services [Member] | Casino Non-gaming [Member]
Revenues from customers	1,148	1,090
Professional Services [Member] | Professional Services [Member]
Revenues from customers	0	52
Professional Services [Member] | Aircraft Modification [Member]
Revenues from customers	0	0
Professional Services [Member] | Aircraft Avionics [Member]
Revenues from customers	0	0
Professional Services [Member] | Special Mission Electronics [Member]
Revenues from customers	0	0
Aerospace Products [Member]
Revenues from customers	10,592	8,144
Aerospace Products [Member] | Percentage of Completion Contracts [Member]
Revenues from customers	6,080	5,213
Aerospace Products [Member] | Transferred at Point in Time [Member]
Revenues from customers	4,512	2,931
Aerospace Products [Member] | Casino [Member]
Revenues from customers	0	0
Aerospace Products [Member] | Sportsbook [Member]
Revenues from customers	0	0
Aerospace Products [Member] | Casino Non-gaming [Member]
Revenues from customers	0	0
Aerospace Products [Member] | Professional Services [Member]
Revenues from customers	0	0
Aerospace Products [Member] | Aircraft Modification [Member]
Revenues from customers	7,106	5,483
Aerospace Products [Member] | Aircraft Avionics [Member]
Revenues from customers	461	744
Aerospace Products [Member] | Special Mission Electronics [Member]
Revenues from customers	3,025	1,917
North America [Member]
Revenues from customers	15,603	15,992
North America [Member] | Professional Services [Member]
Revenues from customers	9,236	9,041
North America [Member] | Aerospace Products [Member]
Revenues from customers	6,367	6,951
Europe [Member]
Revenues from customers	3,535	952
Europe [Member] | Professional Services [Member]
Revenues from customers	0	0
Europe [Member] | Aerospace Products [Member]
Revenues from customers	3,535	952
Asia [Member]
Revenues from customers	455	4
Asia [Member] | Professional Services [Member]
Revenues from customers	0
Asia [Member] | Aerospace Products [Member]
Revenues from customers	455	4
Australia and Other [Member]
Revenues from customers	235	237
Australia and Other [Member] | Professional Services [Member]
Revenues from customers	0	0
Australia and Other [Member] | Aerospace Products [Member]
Revenues from customers	$ 235	$ 237