Note 15 - Stock-based Compensation - Share-based Award Expense Activity (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Share-based compensation expense	$ 1,251	$ 595
Employee Stock Option [Member]
Share-based compensation expense	56	91
Restricted Stock [Member]
Share-based compensation expense	744	504
Performance Shares [Member]
Share-based compensation expense	$ 451

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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