Note 13 - Quarterly Financial Information (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

Notes Tables

Schedule of Quarterly Financial Information [Table Text Block]

	Quarter Ended
	March 31,			June 30,			September 30,			December 31,
	2015			2015			2015			2015
Revenues	$	18		$	38		$	227		$	21
Gross profit (loss)		18			38			(64	)		(22	)
Operating loss		(2,718	)		(3,751	)		(3,651	)		(3,889	)
Net loss		(4,842	)		(5,990	)		(5,965	)		(7,216	)
Basic and diluted net loss per common share	$	(0.27	)	$	(0.34	)	$	(0.33	)	$	(0.40	)

	Quarter Ended
	March 31,			June 30,			September 30,			December 31,
	2014			2014			2014			2014
Revenues	$	4		$	11		$	305		$	16
Gross profit (loss)		4			11			23			(59	)
Operating loss		(2,648	)		(2,453	)		(2,375	)		(2,883	)
Net loss		(4,648	)		(4,515	)		(4,566	)		(5,106	)
Basic and diluted net loss per common share	$	(0.29	)		(0.28	)	$	(0.28	)	$	(0.30	)