Note 5 - Fair Value Measurements - Fair Value of Financial Assets Measured on a Recurring Basis (Details) - Fair Value, Inputs, Level 1 [Member] - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Cash and cash equivalents:
Money market mutual fund	$ 15,761	$ 6,129
Total	$ 15,761	$ 6,129