Note 9 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Expense (Benefit), Total	$ 269,000	$ (1,737,000)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 465,000	$ 243,000
Unrecognized Tax Benefits, Ending Balance	295,000	$ 275,000	$ 259,000
Unrecognized Tax Benefits, Income Tax Penalties Accrued	28,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	0
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total	1,100,000
Domestic Tax Authority [Member] | Capital Loss Carryforward [Member]
Tax Credit Carryforward, Amount	2,679,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	3,167,000
State and Local Jurisdiction [Member] | Capital Loss Carryforward [Member]
Tax Credit Carryforward, Amount	129,000
Foreign Tax Authority [Member]
Operating Loss Carryforwards, Total	$ 46,000