Note 11 - Warranty Costs - Warranty Costs Accrual (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Warranty accrual	$ 43,932	$ 40,691
Warranty costs accrued during the period	4,805	4,588
Warranty costs paid during the period	(5,237)	(4,774)
Warranty accrual	$ 43,500	$ 40,505