Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Foreign Currency Transaction Gain (Loss), before Tax, Total	$ (310)	$ 953	$ (550)
Goodwill, Impairment Loss	$ 0	0	0
Minimum [Member]
Warranty Term	1 year
Maximum [Member]
Warranty Term	2 years
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	20 years
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	40 years
Computer Equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Computer Equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	8 years
Transportation Equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	5 years
Transportation Equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	20 years
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	5 years
Interest and Other Income [Member]
Foreign Currency Transaction Gain (Loss), before Tax, Total	$ (300)	$ 1,000	$ (600)