Note 7 - Property, Plant, and Equipment - Schedule of Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	Jul. 31, 2024	Apr. 30, 2024
Property, plant, and equipment, gross	$ 84,259	$ 83,918
Accumulated depreciation	(25,319)	(24,331)
Total property, plant and equipment	58,940	59,587
Land [Member]
Property, plant, and equipment, gross	4,224	4,224
Building and Building Improvements [Member]
Property, plant, and equipment, gross	48,230	48,190
Aircraft [Member]
Property, plant, and equipment, gross	5,699	5,599
Machinery and Equipment [Member]
Property, plant, and equipment, gross	7,463	7,484
Furniture and Fixtures [Member]
Property, plant, and equipment, gross	14,611	14,389
Leasehold Improvements [Member]
Property, plant, and equipment, gross	$ 4,032	$ 4,032