Note 9 - Income Taxes - Significant Components of Deferred Tax Liabilities and Assets (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Property and equipment	$ (1,055,000)	$ (564,000)
Total deferred tax liabilities	(1,055,000)	(564,000)
Net operating loss carryforwards	360,000	99,000
Accruals and allowances	41,000	43,000
Lease liabilities	136,000	0
Tax credits	4,000	5,000
Other – net	87,000	50,000
Capital loss carryover	646,000	627,000
Total deferred tax assets	1,274,000	824,000
Valuation allowance	(697,000)	(678,000)
Deferred tax assets net of valuation allowance	577,000	146,000
Net deferred tax liabilities	(478,000)	(418,000)
Deferred income taxes (non-current)	(478,000)	(418,000)
Deferred Tax Liabilities, Net, Total	$ (478,000)	$ (418,000)