CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2016	Dec. 31, 2015
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	152,609,491	152,128,941
Common stock, shares outstanding	151,082,475	150,700,989
Treasury stock shares	1,527,016	1,427,952