Note 8 - Concentration Risk (Details Textual)	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021	Sep. 30, 2022 USD ($)	Sep. 30, 2021	Mar. 31, 2022 USD ($)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents in Excess of FDIC Insured Limits	$ 27,500,000		$ 27,500,000		$ 25,300,000
Maximum [Member]
Cash, FDIC Insured Amount	$ 250,000		$ 250,000
Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Number of Customers	3	3	3	3
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Three Largest Customers [Member]
Concentration Risk, Percentage	90.00%	90.00%	83.00%	86.00%
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Walmart [Member]
Concentration Risk, Percentage	48.00%	32.00%	45.00%	38.00%
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Fred Meyer [Member]
Concentration Risk, Percentage	24.00%	19.00%	22.00%	21.00%
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Amazon [Member]
Concentration Risk, Percentage	18.00%	39.00%	16.00%	27.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Number of Customers			3		3
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Customer One [Member]
Concentration Risk, Percentage			42.00%		69.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Customer Two [Member]
Concentration Risk, Percentage			30.00%		17.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Customer Three [Member]
Concentration Risk, Percentage			22.00%		11.00%
Product Concentration Risk [Member] | Revenue, Product and Service Benchmark [Member]
Number of Product Types	2	2	2	2
Number of Product Categories	2	2	2	2
Product Concentration Risk [Member] | Revenue, Product and Service Benchmark [Member] | Microwave Ovens [Member]
Concentration Risk, Percentage	29.00%	26.00%	34.00%	33.00%
Product Concentration Risk [Member] | Revenue, Product and Service Benchmark [Member] | Audio Products [Member]
Concentration Risk, Percentage	70.00%	73.00%	65.00%	67.00%
Supplier Concentration Risk [Member] | Products for Resale [Member]
Number of Factory Suppliers	2	2	2	2
Supplier Concentration Risk [Member] | Products for Resale [Member] | Two Largest Factory Suppliers [Member]
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Supplier Concentration Risk [Member] | Products for Resale [Member] | Largest Supplier [Member]
Concentration Risk, Percentage	64.00%	84.00%	70.00%	83.00%