Note 11 - Warranty Accrual (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Product Warranty, First Term for Performing Work	2 years
Standard and Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties	$ 50	$ 2,987
Minimum [Member]
Product Warranty, Term for Paying for Work	3 years
Maximum [Member]
Product Warranty, Term for Paying for Work	10 years