Note 11 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Federal, state and foreign net operating losses	$ 75,863	$ 70,286
Research and other credits	4,361	3,655
Operating lease liability	1,237
Accruals and other	2,847	4,317
Total deferred tax assets	84,308	78,258
Less: Valuation allowance	(82,755)	(78,082)
Total net deferred tax assets	1,553	176
Fixed assets	(198)	(176)
Operating lease right of use asset	(1,355)
Total deferred tax liabilities	(1,553)	(176)
Net deferred tax assets (liabilities)