Note 4 - Stockholder's Equity (Deficiency) (Details) - Summary of Employees' Stock Options Activities (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Summary of Employees' Stock Options Activities [Abstract]
Options outstanding	4,042,100	4,080,611
Options outstanding	$ 10.433	$ 9.697
Options outstanding	$ 64,869	$ 95,855
Options outstanding	6 years 17 days	6 years 33 days
Vested and expected to vest	3,932,028
Vested and expected to vest	$ 10.064
Vested and expected to vest	64,408
Vested and expected to vest	5 years 350 days
Options exercisable at the end of the period	2,578,803
Options exercisable at the end of the period	$ 3.488
Options exercisable at the end of the period	$ 57,852
Options exercisable at the end of the period	4 years 118 days
Granted	161,200
Granted	$ 29.880
Exercised	(140,716)
Exercised	$ 3.728
Forfeited	(58,995)
Forfeited	$ 28.659