Note 5 - Balance Sheet Components - Components of Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Property and equipment, gross	$ 60,217	$ 60,071
Property and equipment, gross	60,217	60,071
Less: Accumulated depreciation and amortization	(48,402)	(44,512)
Property and equipment, net	11,815	15,559
Computer Equipment [Member]
Property and equipment, gross	27,781	29,938
Property and equipment, gross	$ 27,781	29,938
Computer Equipment [Member] \| Minimum [Member]
Estimated useful life of property and equipment (Year)	3 years
Computer Equipment [Member] \| Maximum [Member]
Estimated useful life of property and equipment (Year)	4 years
Software, Including Internally Developed Software [Member]
Estimated useful life of property and equipment (Year)	3 years
Property and equipment, gross	$ 25,518	23,389
Property and equipment, gross	25,518	23,389
Leasehold Improvements [Member]
Property and equipment, gross	4,778	4,617
Property and equipment, gross	4,778	4,617
Office Equipment, Furniture and Fixtures [Member]
Property and equipment, gross	2,140	2,127
Property and equipment, gross	$ 2,140	$ 2,127
Office Equipment, Furniture and Fixtures [Member] \| Minimum [Member]
Estimated useful life of property and equipment (Year)	5 years
Office Equipment, Furniture and Fixtures [Member] \| Maximum [Member]
Estimated useful life of property and equipment (Year)	5 years

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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