Note 6 - Product Warranty Reserve (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Beginning balance	$ 237	$ 383	$ 770
Additions charged to Cost of sales	111	515	554
Claims processed	(266)	(661)	(941)
Ending balance	$ 82	$ 237	$ 383