Capital Stock (Details Textuals) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Nov. 30, 2010	Jul. 31, 2010	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Capital Stock (Textuals) [Abstract]
Options and restricted stock, anti-dilutive			1,500,000	3,300,000	1,100,000	2,900,000
Depository shares in separate underwriting		25,300,000
Depositary shares each representing		1/20th interest
Mandatory convertibles preferred stock, Series D		6.00%			6.00%		6.00%
Preferred stock, shares outstanding		1,265,000	1,265,000		1,265,000		1,265,000
Conversion of preferred stock to equity shares ratio, minimum					9.164
Conversion of preferred stock to equity shares ratio, maximum					11.364
Common stock issued	17,300,000
Common stock, shares authorized			860,000,000	430,000,000	860,000,000	430,000,000	860,000,000
Preferred stock, shares authorized			10,000,000	5,000,000	10,000,000	5,000,000	10,000,000
Common stock dividends			$ 58	$ 51	$ 115	$ 101
Dividend paid, Series D preferred stock				$ 19	$ 38	$ 38