Note 8 - Stock-Based Compensation (Details) - Stock Option Activity (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Stock Option Activity [Abstract]
Shares	1,134,026	607,017
Weighted-Average Exercise Price	$ 3.49	$ 2.22
Weighted- Average Remaining Contractual Term (years)	6 years 328 days	5 years 73 days
Aggregate Intrinsic Value	$ 8,716	$ 1,627
Granted	527,718
Granted	$ 4.92
Exercised	(709)
Exercised	$ 1.27
Exercisable at September 30, 2014	581,438
Exercisable at September 30, 2014	$ 2.38
Exercisable at September 30, 2014	4 years 6 months
Exercisable at September 30, 2014	5,123
Vested or expected to vest at September 30, 2014	1,067,423
Vested or expected to vest at September 30, 2014	$ 3.33
Vested or expected to vest at September 30, 2014	6 years 292 days
Vested or expected to vest at September 30, 2014	$ 8,264