Note 2 - Summary of Significant Accounting Policies (Detail) - Stock Option Activity (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Outstanding at December 31, 2011	7,371,304
Outstanding at December 31, 2011 (in Dollars per share)	$ 12.48
Outstanding at June 30, 2012	9,522,146
Outstanding at June 30, 2012 (in Dollars per share)	$ 11.66
Outstanding at June 30, 2012	8 years 186 days
Outstanding at June 30, 2012 (in Dollars)	$ 35,709
Exercisable at June 30, 2012	3,626,119
Exercisable at June 30, 2012 (in Dollars per share)	$ 9.39
Exercisable at June 30, 2012	7 years 244 days
Exercisable at June 30, 2012 (in Dollars)	$ 20,776
Options granted	2,524,701
Options granted (in Dollars per share)	$ 9.75
Options forfeited	(328,966)
Options forfeited (in Dollars per share)	$ 16.09
Options exercised	(44,893)
Options exercised (in Dollars per share)	$ 7.35