Note 3 - Balance Sheet Components - Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Gross Carrying Amount	$ 25,150	$ 25,150
Accumulated Amortization	(19,833)	(19,076)
Intangible assets, net	5,317	6,074
Customer Relationships [Member]
Gross Carrying Amount	6,740	6,740
Accumulated Amortization	(4,421)	(4,145)
Intangible assets, net	$ 2,319	2,595
Customer Relationships [Member] \| Minimum [Member]
Amortization Period (Year)	1 year
Customer Relationships [Member] \| Maximum [Member]
Amortization Period (Year)	9 years
Developed Technology Rights [Member]
Gross Carrying Amount	$ 15,820	15,820
Accumulated Amortization	(13,261)	(12,829)
Intangible assets, net	$ 2,559	2,991
Developed Technology Rights [Member] \| Minimum [Member]
Amortization Period (Year)	4 years
Developed Technology Rights [Member] \| Maximum [Member]
Amortization Period (Year)	6 years
Trade Names [Member]
Gross Carrying Amount	$ 790	790
Accumulated Amortization	(641)	(622)
Intangible assets, net	$ 149	168
Trade Names [Member] \| Minimum [Member]
Amortization Period (Year)	2 years
Trade Names [Member] \| Maximum [Member]
Amortization Period (Year)	4 years
Patents [Member]
Gross Carrying Amount	$ 1,800	1,800
Accumulated Amortization	(1,510)	(1,480)
Intangible assets, net	$ 290	$ 320
Patents [Member] \| Minimum [Member]
Amortization Period (Year)	7 years
Patents [Member] \| Maximum [Member]
Amortization Period (Year)	10 years

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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