Note 8 - Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2014

Earnings Per Share [Abstract]

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

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2014		2013		2014		2013
Options to purchase common stock		3,414		3,519		3,553		3,628
Restricted stock units		149		140		161		144
Performance stock units		6		34		6		34
Employee stock purchase plan shares		54		60		54		60
Total		3,623		3,753		3,774		3,866