Common Stock

3 Months Ended

Mar. 31, 2015

Equity [Abstract]

Common Stock

8. Common Stock

As of March 31, 2015 and December 31, 2014, the Company had 200.0 million shares of $0.01 par value common stock authorized. There were approximately 109.4 million and 106.7 million shares of common stock issued and outstanding as of March 31, 2015 and December 31, 2014, respectively.

The shares reserved for future issuance as of March 31, 2015 and December 31, 2014 consisted of the following:

(in thousands)	March 31, 2015		December 31, 2014
Options to purchase common stock		20,285		19,567
Common stock warrants		741		2,381
Conversion premium on the Notes		25,000		25,000

During the three months ended March 31, 2015, warrants to purchase 1.6 million shares of common stock were exercised in cashless transactions at a weighted average exercise price of $3.00, and 1.2 million shares of common stock were issued. During the three months ended March 31, 2014, warrants to purchase 0.3 million shares of common stock were exercised in cash and cashless transactions at a weighted average exercise price of $3.45, and 0.3 million shares of common stock were issued.