CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Common stock, shares authorized	300,000,000	300,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares issued	118,469,000	119,378,000
Common stock, shares outstanding	118,469,000	119,378,000