Note 7 - Stock-based Compensation - Stock-based Compensation Expense and Related Income Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock-based compensation expense, gross	$ 6,661	$ 8,303	$ 5,099
Income tax benefit at our statutory rate associated with stock-based compensation	(1,692)	(3,238)	(1,989)
Stock-based compensation expense, net	$ 4,969	$ 5,065	$ 3,110

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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-Publisher FASB
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