Note 9 - Stock Incentive Plans - Share-based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Total compensation cost for share-based payments	$ 261	$ 700	$ 842	$ 2,147
Weighted average grant-date fair value of equity instruments granted (per share) (in dollars per share)	$ 2.27	$ 1.72	$ 2.26	$ 1.74
Total fair value of shares vested during the period	$ 83	$ 70	$ 2,369	$ 1,954
Unamortized share-based payments			$ 2,276	$ 2,092
Weighted average period (in years) to be recognized as expense (Year)			1 year 255 days	1 year 146 days