CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) (USD $)	1 Months Ended				3 Months Ended		9 Months Ended
	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
CONDENSED CONSOLIDATED STATEMENTS OF EQUITY
Common dividends, per share (in dollars per share)	$ 0.50	$ 0.50	$ 0.50	$ 0.50	$ 0.50	$ 0.48	$ 1.50	$ 1.44