Note 2 - Summary of Significant Accounting Policies (Details) - Stock Option Activity (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Stock Option Activity [Abstract]
Outstanding at December 31, 2012	9,463,657
Outstanding at December 31, 2012 (in Dollars per share)	$ 11.76
Outstanding at September 30, 2013	8,126,850
Outstanding at September 30, 2013 (in Dollars per share)	$ 12.49
Outstanding at September 30, 2013	7 years 219 days
Outstanding at September 30, 2013 (in Dollars)	$ 111,758
Exercisable at September 30, 2013	4,788,361
Exercisable at September 30, 2013 (in Dollars per share)	$ 11.71
Exercisable at September 30, 2013	7 years 36 days
Exercisable at September 30, 2013 (in Dollars)	$ 68,388
Options granted	525,100
Options granted (in Dollars per share)	$ 16.68
Options forfeited	(344,052)
Options forfeited (in Dollars per share)	$ 15.92
Options exercised	(1,517,855)
Options exercised (in Dollars per share)	$ 8.62