Note 11 - Net Loss Per Share Attributable to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2015

Notes Tables

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Year Ended December 31,
	2015		2014			2013
Convertible preferred stock		-		7,581	(a)		4,254
Common stock warrants		-		660	(a)		660
Outstanding stock options		2,200		1,236			607
Convertible notes		-		243	(a)		243
		2,200		9,720			5,764