Net Loss Per Common Share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Schedule of Securities Excluded from Computation of Diluted Loss Per Share

Securities excluded from the calculation of diluted loss per share are shown in the chart below:

	Years Ended December 31,
(in thousands)	2016		2015		2014
Common stock warrants		—		—		2,381
Outstanding options to purchase common stock		19,025		19,211		19,567
Conversion of the Convertible Notes		12,158		25,000		25,000