Note 2 - Summary of Significant Accounting Policies (Details) - Stock Option Activity (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Option Activity [Abstract]
Outstanding	4,965.947	7,334,745	9,463,657	7,371,304
Outstanding - weighted average exercise price	$ 12.96	$ 12.33	$ 11.76	$ 12.48
Outstanding - weighted average remaining contractual term	6 years 219 days
Outstanding - aggregate intrinsic value	$ 142,193
Options granted	629,775	621,100	2,933,701
Options granted - weighted average exercise price	$ 32.72	$ 18.16	$ 10.28
Options forfeited	(204,348)	(520,139)	(552,228)
Options forfeited - weighted average exercise price	$ 20.42	$ 15.38	$ 15.28
Options exercised	(2,794,225)	(2,229,873)	(289,120)
Options exercised - weighted average exercise price	$ 15.20	$ 10.85	$ 8.46
Exercisable at December 31, 2014	3,676,807	4,700,000
Exercisable at December 31, 2014	$ 9.95
Exercisable at December 31, 2014	6 years
Exercisable at December 31, 2014	116,347
Expected to vest after December 31, 2014	1,095,769
Expected to vest after December 31, 2014	$ 21.54
Expected to vest after December 31, 2014	8 years 109 days
Expected to vest after December 31, 2014	$ 21,969