Note 7 - Net Income Per Share (Details) - Calculation of Earnings Per Share (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Calculation of Earnings Per Share [Abstract]
Net income (in Dollars)	$ 4,552	$ 4,820	$ 9,283	$ 8,319
Basic weighted average common shares outstanding	29,650	28,560	29,501	28,472
Dilutive effect of equity incentive plans	1,504	1,000	1,484	831
Diluted weighted average common shares outstanding	31,154	29,560	30,985	29,303
Net income per share:
Basic (in Dollars per share)	$ 0.15	$ 0.17	$ 0.31	$ 0.29
Diluted (in Dollars per share)	$ 0.15	$ 0.16	$ 0.30	$ 0.28