CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Common stock, shares authorized	200,000,000	200,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares outstanding	66,496,654	68,998,069
Treasury stock, shares	5,065,091	1,987,073