Note F - Property, Plant and Equipment (Details Textual)	Dec. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Oct. 31, 2022 USD ($)	May 25, 2021 USD ($) ft² a
Buildings and Improvements, Gross	$ 29,266,000	$ 28,550,000
Construction in Progress, Gross	4,174,000	$ 1,167,000
Capital Expenditures, Expected Cost	3,800,000
Facility in Sinton, Texas [Member]
Area of Land (Acre) | a				26.5
Lessee, Operating Lease, Term of Contract (Year)				99 years
Annual Rental Payment				$ 1
Capitalized Property Plant and Equipment [Member]
Buildings and Improvements, Gross			$ 22,200,000
Facility in Sinton, Texas [Member]
Area of Real Estate Property (Square Foot) | ft²				70,000
Building Expansion Project [Member]
Construction in Progress, Gross	4,200,000
Upgrade of Decatur, AL Processing Line [Member]
Construction in Progress, Gross	1,500,000
Repair and Expansion of Storage Yard at Decatur Facility [Member]
Construction in Progress, Gross	$ 1,800,000