Note 9 - Net Loss Per Share Attributable to Common Stockholders (Tables)

3 Months Ended

Mar. 31, 2015

Earnings Per Share [Abstract]

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

	Three Months Ended March 31,
	2015		2014
Convertible preferred stock		-		4,254
Common stock warrants		-		660
Outstanding stock options		1,635		607
Outstanding ESPP shares		3		-
Convertible notes		-		249
		1,638		5,770