Note 7 - Customer and Geographic Information - Revenues by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member] | UNITED STATES
Revenues	$ 9,518	$ 11,436	$ 21,640	$ 21,750
Receivables percentage by major customer	36.00%	49.00%	42.00%	43.00%
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member] | TAIWAN, PROVINCE OF CHINA
Revenues	$ 5,725	$ 2,160	$ 7,909	$ 3,279
Receivables percentage by major customer	21.00%	9.00%	15.00%	7.00%
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member] | GERMANY
Revenues	$ 3,994	$ 6,345	$ 7,028	$ 12,609
Receivables percentage by major customer	15.00%	27.00%	14.00%	25.00%
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member] | KOREA, REPUBLIC OF
Revenues	$ 2,184	$ 627	$ 5,497	$ 7,545
Receivables percentage by major customer	8.00%	3.00%	11.00%	15.00%
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member] | Rest of the World [Member]
Revenues	$ 5,267	$ 2,642	$ 9,695	$ 4,844
Receivables percentage by major customer	20.00%	12.00%	18.00%	10.00%
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member]
Revenues	$ 26,688	$ 23,210	$ 51,769	$ 50,027
Receivables percentage by major customer	100.00%	100.00%	100.00%	100.00%
Revenues	$ 26,688	$ 23,210	$ 51,769	$ 50,027