Note 8 - Income Taxes (Detail) - Deferred Tax Assets and Liabilities (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Research tax credits	$ 4,930	$ 5,162
Stock compensation	5,487	6,553
Other costs not currently deductible	2,424	2,767
Depreciation and amortization	317	774
Total deferred tax assets	13,158	15,256
Valuation allowance	(12,488)	(14,596)
Net deferred tax assets	$ 670	$ 660