Note 15 - Segment Reporting and Sales by Major Customer - Professional Services (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021
Revenues	$ 73,473	$ 61,480
Interest expense	2,689	3,138
Depreciation and amortization	2,815	3,542
Gaming [Member]
Revenues	38,769	29,951
Interest expense	2,440	2,847
Depreciation and amortization	2,283	3,060
Aircraft Modification [Member]
Revenues	21,399	21,750
Interest expense	215	251
Depreciation and amortization	181	191
Aircraft Avionics [Member]
Revenues	2,373	2,583
Interest expense	0	0
Depreciation and amortization	5	7
Special Mission Electronics [Member]
Revenues	10,554	6,942
Interest expense	23	27
Depreciation and amortization	161	135
Product and Service, Other [Member]
Revenues	378	254
Interest expense	11	13
Depreciation and amortization	$ 185	$ 149