Common Stock (Tables)

3 Months Ended

Mar. 31, 2014

Equity [Abstract]

Schedule of Shares Reserved for Future Issuance

The shares reserved for future issuance as of March 31, 2014 and December 31, 2013 consisted of the following:

(in thousands)	March 31, 2014		December 31, 2013
Common stock warrants		2,443		2,777
Options to purchase common stock		22,243		20,107
Conversion of the Notes		25,000		25,000