Note 7 - Income Taxes (Details) - Differences Between the Company's Effective Tax Rate and the Statutory Tax Rate (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Differences Between the Company's Effective Tax Rate and the Statutory Tax Rate [Abstract]
Income tax benefit at federal statutory rate (35%)	$ (15,816)	$ (10,538)	$ (13,678)
State and local income taxes net of federal tax benefit	(1,286)	(839)	(1,470)
Permanent items	258	738	754
Rate change	22	1,892	1,147
Expiration of attribute carryforwards	373	242	5,135
Research and development tax credits	(748)	(1,206)	829
Other	(115)	1,144	281
Change in valuation allowance	$ 17,312us-gaap_IncomeTaxExpenseBenefit	$ 8,567us-gaap_IncomeTaxExpenseBenefit	$ 7,002us-gaap_IncomeTaxExpenseBenefit

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Income tax reconciliation income tax expense benefit expiration of carryforwards.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) in the income tax rates.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to state and local income tax expense (benefit).

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