Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Common stock, shares outstanding	75,375,027
General Partners' Capital Account, Units Outstanding	75,375,027
Limited Partners' Capital Account, Units Outstanding	4,186,369
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	75,375,027	75,267,675
Common stock, shares outstanding	75,375,027	75,267,675
Limited Partner [Member]
General Partners' Capital Account, Units Outstanding	75,375,027	75,267,675
Limited Partners' Capital Account, Units Outstanding	4,186,369	4,191,152