Note 11 - Warranty Accrual and Payment Activity (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Balance at beginning of period	$ 15,328,000	$ 18,346,000
Expense provisions	1,452,000	1,115,000
Cash payments	(2,915,000)	(1,700,000)
Standard and Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties	2,987,000	0
Balance at end of period	$ 16,852,000	$ 17,761,000