Net Income (Loss) Per Share

12 Months Ended

Dec. 31, 2014

Earnings Per Share [Abstract]

Earnings Per Share [Text Block]

4. Net Income (Loss) Per Share

Basic net income (loss) per share is calculated by dividing the net income (loss) attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents. Diluted net income (loss) per share is computed by dividing the net income (loss) attributable to common stockholders by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method and the if-converted method. For purposes of this calculation, stock options, warrants, PRSUs, RSUs and shares to be purchased under the Company’s 2010 Employee Stock Purchase Plan (“ESPP”) are considered to be common stock equivalents and are only included in the calculation of diluted net income (loss) per share when their effect is dilutive.

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

These common stock equivalents were excluded from the determination of diluted net loss per share for the years ended December 31, 2012 and December 31, 2013, due to their anti-dilutive effect on earnings.

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