Note 6 - Net Income Per Share (Details) - Net Income Per Share Basic And Diluted (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net Income Per Share Basic And Diluted [Abstract]
Net income (in Dollars)	$ 11,221	$ 7,410	$ 26,635	$ 15,399
Weighted average outstanding shares used to compute basic net income per share	38,785	37,910	38,646	37,079
Effect of dilutive securities	942	1,099	972	1,340
Weighted average outstanding shares used to compute diluted net income per share	39,727	39,009	39,618	38,419
Net income per share - basic (in Dollars per share)	$ 0.29	$ 0.20	$ 0.69	$ 0.42
Net income per share - diluted (in Dollars per share)	$ 0.28	$ 0.19	$ 0.67	$ 0.40