Net Loss Per Share Attributable to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2013

Basic and Diluted 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	)

Anti-Dilutive Shares Excluded from Calculation of Diluted Net Loss Per Share

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