Note 4 - Balance Sheet Components (Details) - Roll-Forward of the Warranty Reserve - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Roll-Forward of the Warranty Reserve [Abstract]
Balance at beginning of period	$ 205	$ 290	$ 240	$ 451
Warranty provision for product sales	91	78	246	207
Settlements made			(153)	(74)
Unused warranty provision	(28)	(128)	(65)	(344)
Balance at end of period	$ 268	$ 240	$ 268	$ 240