Common Stock

6 Months Ended

Jun. 30, 2015

Equity [Abstract]

Common Stock

8. Common Stock

As of June 30, 2015 and December 31, 2014, the Company had 200.0 million shares of $0.01 par value common stock authorized. There were approximately 110.8 million and 106.7 million shares of common stock issued and outstanding as of June 30, 2015 and December 31, 2014, respectively.

The shares reserved for future issuance as of June 30, 2015 and December 31, 2014 consisted of the following:

(in thousands)	As of June 30, 2015		As of December 31, 2014
Options to purchase common stock		19,426		19,567
Common stock warrants		377		2,381
Conversion premium on the Notes		25,000		25,000

During the six months ended June 30, 2015, warrants to purchase 2.0 million shares of common stock were exercised in cash and cashless transactions at a weighted average exercise price of $3.00, and 1.5 million shares of common stock were issued. During the six months ended June 30, 2014, warrants to purchase 0.4 million shares of common stock were exercised in cash and cashless transactions at a weighted average exercise price of $3.41, and 0.3 million shares of common stock were issued.