Net Income (Loss) Per Share (Tables)

12 Months Ended

Dec. 31, 2014

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

As of December 31, 2012, 2013 and 2014 the following number of potential common stock equivalents were outstanding:

Common stock equivalents


	Year Ended December 31,
	2012		2013		2014
Outstanding common stock options		3,879,239		5,246,465		5,096,674
Outstanding warrants		133,968		34,647		34,647
Outstanding PRSUs		273,988		270,649		245,396
Outstanding RSUs		—		—		161,439
Shares to be purchased under the ESPP		—		—		2,894
Total		4,287,195		5,551,761		5,541,050

Schedule of Weighted Average Number of Shares [Table Text Block]

The following weighted-average outstanding common stock options, warrants, RSUs and shares to be purchased under the ESPP were added to basic weighted-average common shares outstanding for the year ended December 31, 2014 to calculate diluted weighted-average shares outstanding because of their dilutive effect:


	Year Ended December 31, 2014
Outstanding common stock options		1,494,796
Outstanding warrants		5,433
Outstanding RSUs		14,128
Shares to be purchased under the ESPP		1,392
Total		1,515,749