Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Components of tax charge
Ordinary income estimated at annual effective tax rate before tax	$ 123		$ 317
Ordinary income taxed at estimated annual effective tax rate tax amount	(31)		(79)
Ordinary income taxed at estimated annual effective tax rate	25.00%		25.00%
Items where tax effect is treated discretely:
Make-whole on repurchase and redemption of senior notes and write-off of unamortized debt issuance costs			(171)
Current tax on make-whole on repurchase and redemption of senior notes and write-off of unamortized debt issuance costs			47
Effective Income Tax Rate on the make-whole on repurchase and redemption of senior notes and write-off of unamortized debt issuance costs			27.00%
Non-taxable gain on disposal of operations before tax		(2)	4	(2)
Non-taxable gain on disposal of operations tax			0
Non-taxable gain on disposal of operations effective tax rate			0.00%
Income before income taxes as reported	123	128	150	386
Tax amount as reported	$ (31)	$ (35)	$ (32)	$ (102)
Effective tax rate	25.00%		21.00%
Income Taxes (Textuals) [Abstract]
Ordinary income taxed at estimated annual effective tax rate	25.00%		25.00%
Effective tax rate absent impact of 2011 operational review			25.00%