Note 6 - Stock-based Compensation (Details) - Stock-based Compensation Expense and Related Income Tax Benefit - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Stock-based Compensation Expense and Related Income Tax Benefit [Abstract]
Stock-based compensation expense, gross	$ 1,009	$ 980	$ 2,002	$ 3,052
Income tax benefit at our statutory rate associated with stock-based compensation	(394)	(382)	(781)	(1,190)
Stock-based compensation expense, net	$ 615	$ 598	$ 1,221	$ 1,862