CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
CONSOLIDATED BALANCE SHEETS
Preferred stock shares, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock shares, authorized	50,000,000	50,000,000
Preferred stock shares, issued	0	0
Preferred stock shares, outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	450,000,000	450,000,000
Common stock, shares issued	151,134,022	148,545,150
Common stock, shares outstanding	149,853,512	147,538,519
Treasury stock shares	1,280,510	1,006,631