CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	117,500,000	58,750,000
Common stock, shares issued	34,733,117	25,599,550
Common stock, shares outstanding	34,733,117	25,599,550
2.5 Percent Convertible Notes
Convertible notes, interest rate (as a percent)	2.50%	2.50%