Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2016	Dec. 31, 2015
Common stock, shares outstanding	75,524,086
General Partners' Capital Account, Units Outstanding	75,524,086
Limited Partners' Capital Account, Units Outstanding	4,159,003
Parent Company [Member]
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	75,505,025	75,408,571
Common stock, shares outstanding	75,505,025	75,408,571
Limited Partner [Member]
General Partners' Capital Account, Units Outstanding	75,505,025	75,408,571
Limited Partners' Capital Account, Units Outstanding	4,162,163	4,162,996