Note 9 - Income Taxes (Details Textual) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount	$ 600,000	$ 600,000
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Cash and Certain Other Net Current Assets, Percent		15.50%
Effective Income Tax Rate Reconciliation, Repatriation of Other Foreign Remaining Earnings, Percent		8.00%
Operating Loss Carryforwards, Total	13,900,000	$ 13,900,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	35.00%	35.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			$ (1,800,000)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount			12,700,000
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	56,300,000	$ 56,300,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 300,000	$ 300,000	$ 300,000