Note 2 - Summary of Significant Accounting Policies (Details) - Stock Option Activity (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Stock Option Activity [Abstract]
Outstanding	4,350,127	4,965,947
Outstanding - weighted average exercise price	$ 12.95	$ 12.96
Exercisable at March 31, 2015	3,745,257
Exercisable at March 31, 2015	$ 10.26
Exercisable at March 31, 2015	5 years 328 days
Exercisable at March 31, 2015	$ 117,454
Options granted	30,000
Options granted	$ 40.22
Options forfeited	(15,000)
Options forfeited	$ 25.44
Options exercised	(630,820)
Options exercised	$ 14.04