Note 4 - 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		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net Income Per Share Basic And Diluted [Abstract]
Net income (in Dollars)	$ 6,397	$ 5,489	$ 15,415	$ 7,989
Weighted average outstanding shares used to compute basic net income per share	38,684	37,053	38,577	36,657
Effect of dilutive securities	924	1,186	986	1,362
Weighted average outstanding shares used to compute diluted net income per share	39,608	38,239	39,563	38,019
Net income per share - basic (in Dollars per share)	$ 0.17	$ 0.15	$ 0.40	$ 0.22
Net income per share - diluted (in Dollars per share)	$ 0.16	$ 0.14	$ 0.39	$ 0.21