Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Computation of Net (Loss) Income Per Share

Net loss per share was computed by dividing net loss by the weighted average number of common shares outstanding for the years ended December 31, 2017, 2016, and 2015:

	Year Ended December 31,
	2017			2016			2015
Net loss	$	(91,248	)	$	(69,770	)	$	(52,642	)
Weighted average shares—basic	85,115,592			72,824,070			64,882,417
Net loss per share—basic	$	(1.07	)	$	(0.96	)	$	(0.81	)
Weighted average shares—diluted	85,115,592			72,824,070			64,882,417
Net loss per share—diluted	$	(1.07	)	$	(0.96	)	$	(0.81	)

Schedule of Securities Excluded from Calculation of Net (Loss) per Share

The below outstanding securities were excluded from the above calculation of net loss per share because their impact under the "treasury stock method" and "if-converted method" would have been anti-dilutive due to our net loss per share for the years ended December 31, 2017, 2016, and 2015, as summarized below:

	Year Ended December 31,
	2017	2016	2015
2018 Convertible Notes	3,854,959	10,454,799	11,401,284
Common stock options	3,668,662	1,294,594	1,441,086
Restricted stock awards	1,562,918	2,147,157	2,173,615
Common stock warrants	138,277	—	9,357
Preferred stock*	—	—	40,000
Total	9,224,816	13,896,550	15,065,342

* In June 2016, our then 20 outstanding shares of Series E convertible voting preferred stock were converted (at the election of the preferred stockholders) into an aggregate of 40,000 common shares (see Note 7 - Series E Preferred Stock).