Net Loss Per Share Attributable to Common Stockholders

12 Months Ended

Dec. 31, 2013

Earnings Per Share [Abstract]

Net Loss Per Share Attributable to Common Stockholders

NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS

The following table presents the basic and diluted loss per share attributable to common stockholders (in thousands, except per share amounts):

	For the Years Ended December 31,
	2013			2012			2011
Net loss attributable to common stockholders	$	(40,426	)	$	(31,390	)	$	(69,108	)
Weighted-average shares of common stock outstanding, excluding shares issued upon early exercise of unvested options and unvested restricted stock	51,427			49,929			39,824
Net loss per share attributable to common stockholders—basic and diluted	$	(0.79	)	$	(0.63	)	$	(1.74	)

The following table presents the number of anti-dilutive shares excluded from the calculation of diluted net loss per share attributable to common stockholders (in thousands):

	December 31,
	2013	2012	2011
Options to purchase common stock and restricted stock units	7,730	7,331	5,845
Convertible notes	4,682	—	—
Common stock warrants	4,682	—	130
Shares issued for purchase consideration held in escrow	—	16	—
Common stock subject to repurchase right	—	10	30
Other restricted common stock	12	31	—
Total shares excluded from net loss per share attributable to common stockholders	17,106	7,388	6,005

Under the treasury stock method, the convertible notes and common stock warrants will have a dilutive impact on net earnings per share when the average stock price for the period exceeds the respective conversion prices and the Company has net income attributable to common stockholders. The Company also entered into note hedge transactions (“Note Hedges”) in connection with the convertible notes with respect to its common stock to minimize the impact of potential economic dilution upon conversion of the convertible notes. The Note Hedges were outstanding as of December 31, 2013. Since the beneficial impact of the Note Hedges were anti-dilutive, they were excluded from the calculation of diluted net income (loss) per share. See Note 9 of the Notes to Consolidated Financial Statements.