CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) (USD $)	1 Months Ended			3 Months Ended		6 Months Ended
	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
CONDENSED CONSOLIDATED STATEMENTS OF EQUITY
Common dividends, per share (in dollars per share)	$ 0.50	$ 0.50	$ 0.50	$ 0.50	$ 0.48	$ 1.00	$ 0.96