Note 8 - Net Loss Per Share (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
Options to purchase common stock		3,164		3,693
Restricted stock units		318		170
Performance stock units		62		34
Employee stock purchase plan shares		33		21
Total		3,577		3,918