Note 2 - Summary of Significant Accounting Policies (Detail) - Stock Option Activity (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Outstanding at December 31, 2011	7,371,304
Outstanding at December 31, 2011 (in Dollars per share)	$ 12.48
Outstanding at September 30, 2012	9,440,707
Outstanding at September 30, 2012 (in Dollars per share)	$ 11.69
Outstanding at September 30, 2012	8 years 109 days
Outstanding at September 30, 2012 (in Dollars)	$ 45,609
Exercisable at September 30, 2012	3,745,779
Exercisable at September 30, 2012 (in Dollars per share)	$ 9.47
Exercisable at September 30, 2012	7 years 6 months
Exercisable at September 30, 2012 (in Dollars)	$ 26,040
Options granted	2,662,101
Options granted (in Dollars per share)	$ 9.89
Options forfeited	(156,963)
Options forfeited (in Dollars per share)	$ 8.03
Options exercised	(435,735)
Options exercised (in Dollars per share)	$ 15.42