Note 17 - Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock-based compensation expense before income taxes	$ 4,027	$ 2,892	$ 2,473
Less: deferred tax benefit	(846)	(607)	(866)
Reduction of net income	$ 3,181	$ 2,285	$ 1,607

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.

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