Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Common stock, shares outstanding	75,379,381
General Partners' Capital Account, Units Outstanding	75,379,381
Limited Partners' Capital Account, Units Outstanding	4,185,065
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	75,379,381	75,267,675
Common stock, shares outstanding	75,379,381	75,267,675
Limited Partner [Member]
General Partners' Capital Account, Units Outstanding	75,379,381	75,267,675
Limited Partners' Capital Account, Units Outstanding	4,185,065	4,191,152