Note 13 - Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Unrecognized tax benefit, beginning of period	$ 7,239	$ 6,394
Increase in unrecognized tax benefit for positions taken in current period	704	845
Unrecognized tax benefit, end of period	$ 7,943	$ 7,239