Note 1 - Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2015

Notes Tables

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30
	2015		2014		2015		2014
Research and development	$	701	$	2,269	$	1,677	$	2,810
General and administrative		185		255		1,678		2,162
Total share-based compensation expense	$	886	$	2,524	$	3,355	$	4,972