Note 10 - Warranty Costs (Details) - Warranty Costs Accrual - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Warranty Costs Accrual [Abstract]
Warranty accrual, beginning of the period	$ 13,584	$ 13,811
Warranty costs accrued during the period	4,359	2,812
Warranty costs paid during the period	(4,397)	(3,277)
Warranty accrual, end of the period	$ 13,546	$ 13,346