Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Provision for Doubtful Accounts		$ 68	$ 0
Inventory Write-down		251	226
Depreciation		618	370
Foreign Currency Transaction Gain (Loss), before Tax		$ 146	$ (16)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	34.00%
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Thermal Products and Mechanical Products [Member]
Equipment Leased To Customers Initial Term		180 days
Minimum [Member]
Property, Plant and Equipment, Useful Life		1 year
Maximum [Member]
Property, Plant and Equipment, Useful Life		10 years