Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2016

Earnings Per Share [Abstract]

Schedule of basic and diluted net loss per share

Basic and diluted net loss per share is calculated as follows (in thousands, except share and per share numbers):

	Three Months Ended June 30,						Six Months Ended June 30,
	2016			2015			2016			2015
Numerator:
Net loss	$	(43,435	)	$	(22,965	)	$	(83,898	)	$	(40,022	)
Loss attributable to common stockholders - basic and diluted	$	(43,435	)	$	(22,965	)	$	(83,898	)	$	(40,022	)
Denominator:
Weighted-average number of common shares used in loss per share - basic and diluted	43,042,883			37,895,651			43,027,903			37,089,642
Loss per share - basic and diluted	$	(1.01	)	$	(0.61	)	$	(1.95	)	$	(1.08	)

Schedule of potentially dilutive securities excluded from the computation of diluted weighted-average shares outstanding

	Three Months Ended June 30,		Six Months Ended June 30,
	2016	2015	2016	2015
Options to purchase common stock	5,773,589	3,747,303	5,373,641	3,562,712
Warrants	631,588	846,720	631,588	979,434
Restricted stock units	55,929	—	27,964	—
Performance units	—	—	—	—