Note 8 - Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2016

Notes Tables

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

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	201 6		201 5		201 6		201 5
Options to purchase common stock		1,993		2,618		2,059		2,903
Restricted stock units		448		295		426		305
Performance stock units		151		96		144		96
Employee stock purchase plan shares		83		58		83		58
Total		2,675		3,067		2,712		3,362