Note 11 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	34.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability		$ (1,743)
Effective Income Tax Rate Reconciliation, Federal Transition Tax Payable, Amount		$ 476
Transition Tax Rate on Undistributed Foreign Earnings		14.00%
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ 370	(15)
Liability for Uncertainty in Income Taxes, Current		$ 0	$ 0
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%