Note 4 - Balance Sheet Components (Details) - Roll-Forward of the Warranty Reserve - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Roll-Forward of the Warranty Reserve [Abstract]
Balance at beginning of period	$ 296	$ 334	$ 240	$ 451
Warranty provision for product sales	81	68	155	128
Settlements made	(154)		(154)	(74)
Unused warranty provision	(18)	(112)	(36)	(215)
Balance at end of period	$ 205	$ 290	$ 205	$ 290