Subsequent Events

12 Months Ended

Dec. 31, 2014

Subsequent Events [Abstract]

Subsequent Events

14. Subsequent Events

On January 14, 2015, we completed an underwritten public offering of 34.5 million shares (including the exercise of the underwriters’ 30-day option to purchase an additional 4.5 million shares) of our common stock, resulting in net proceeds of approximately $480 million, after deducting estimated offering expenses.