Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014 Parent Company [Member]	Dec. 31, 2013 Parent Company [Member]	Sep. 30, 2014 Limited Partner [Member]	Dec. 31, 2013 Limited Partner [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	75,242,266	74,830,726
Common stock, shares outstanding	75,242,266	74,830,726
General Partners' Capital Account, Units Outstanding			75,242,266	74,830,726
Limited Partners' Capital Account, Units Outstanding			4,202,123	4,227,384