Note 7 - Income Taxes (Details) - Components of Deferred Tax Assets and Liabilities (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets:
Net federal and state operating losses	$ 135,922	$ 119,940
Research and development credits	38,096	37,348
Fixed assets	1,073	1,119
Reserve for inventories		1,612us-gaap_DeferredTaxAssetsInventory
Deferred revenue	3,798us-gaap_DeferredTaxAssetsDeferredIncome	2,151us-gaap_DeferredTaxAssetsDeferredIncome
Stock-based compensation	7,086	5,282
Other	1,178us-gaap_DeferredTaxAssetsOther	311us-gaap_DeferredTaxAssetsOther
Total deferred tax assets	187,153us-gaap_DeferredTaxAssetsGross	167,763us-gaap_DeferredTaxAssetsGross
Deferred tax liabilities:
Foreign currency derivative	(2,285)	(207)
Total deferred tax liabilities	(2,285)us-gaap_DeferredIncomeTaxLiabilities	(207)us-gaap_DeferredIncomeTaxLiabilities
Valuation allowance	$ (184,868)	$ (167,556)

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from unrealized losses on foreign currency transactions.

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