Note 11 - Income Taxes - Deferred Income Tax Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Temporary differences:
Property and equipment	$ (993,000)	$ (706,000)
Intangible assets	(10,000)	(9,000)
Inventory reserve	79,000	24,000
Accrued expenses and inventory	216,000	250,000
Basis difference in investments	35,000	35,000
Foreign exchange	11,000	40,000
AMT/Foreign tax credits	42,000	0
State income taxes	(171,000)	(117,000)
Net deferred income tax liabilities	$ (791,000)	$ (563,000)