Consolidated Statements of Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Limited Partner [Member]
Distribution Made to Member or Limited Partner, Distributions Declared, Per Unit	$ 2.8150	$ 2.6750	$ 2.5425
Parent Company [Member]
Common Stock, Dividends, Per Share, Declared	$ 2.8150	$ 2.6750	$ 2.5425
Distribution Made to Member or Limited Partner, Distributions Declared, Per Unit	$ 2.8150	$ 2.6750	$ 2.5425