Note 3 - Balance Sheet Components - Intangible Assets (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Customer Relationships [Member] | Minimum [Member]
Amortization Period	1 year
Customer Relationships [Member] | Maximum [Member]
Amortization Period	9 years
Customer Relationships [Member]
Gross Carrying Amount	$ 5,920,000	$ 5,920,000
Accumulated Amortization	(3,617,000)	(3,547,000)
Finite-Lived Intangible Assets, Net	$ 2,303,000	2,373,000
Developed Technology Rights [Member] | Minimum [Member]
Amortization Period	4 years
Developed Technology Rights [Member] | Maximum [Member]
Amortization Period	6 years
Developed Technology Rights [Member]
Gross Carrying Amount	$ 14,100,000	14,100,000
Accumulated Amortization	(12,072,000)	(11,976,000)
Finite-Lived Intangible Assets, Net	$ 2,028,000	2,124,000
Trade Names [Member] | Minimum [Member]
Amortization Period	2 years
Trade Names [Member] | Maximum [Member]
Amortization Period	4 years
Trade Names [Member]
Gross Carrying Amount	$ 610,000	610,000
Accumulated Amortization	(545,000)	(533,000)
Finite-Lived Intangible Assets, Net	$ 65,000	77,000
Order or Production Backlog [Member]
Amortization Period	1 year
Gross Carrying Amount	$ 100,000	100,000
Accumulated Amortization	(71,000)	(46,000)
Finite-Lived Intangible Assets, Net	$ 29,000	54,000
Patents [Member] | Minimum [Member]
Amortization Period	7 years
Patents [Member] | Maximum [Member]
Amortization Period	10 years
Patents [Member]
Gross Carrying Amount	$ 1,800,000	1,800,000
Accumulated Amortization	(1,410,000)	(1,400,000)
Finite-Lived Intangible Assets, Net	$ 390,000	400,000
Other Intangible Assets [Member]
Amortization Period	4 years
Gross Carrying Amount	$ 255,000	255,000
Accumulated Amortization	$ (255,000)	$ (255,000)
Finite-Lived Intangible Assets, Net
Gross Carrying Amount	$ 22,785,000	$ 22,785,000
Accumulated Amortization	(17,970,000)	(17,757,000)
Finite-Lived Intangible Assets, Net	$ 4,815,000	$ 5,028,000