Goodwill (Details) (USD $) In Millions	6 Months Ended	12 Months Ended
Jun. 30, 2011	Dec. 31, 2010
Changes in the carrying amount of goodwill by operating segment
Goodwill, Beginning Balance	$ 3,294	$ 3,277
Purchase price allocation adjustments	2	6
Other movements	(1)	(3)
Foreign exchange	22	14
Goodwill, Ending Balance	3,317	3,294
Goodwill (Textuals) [Abstract]
Tax Benefit Arising On The Exercise Of Fully Vested Stock Options	1	3
Global [Member]
Changes in the carrying amount of goodwill by operating segment
Goodwill, Beginning Balance	1,063	1,065
Other movements	60
Foreign exchange	3	(2)
Goodwill, Ending Balance	1,126	1,063
North America [Member]
Changes in the carrying amount of goodwill by operating segment
Goodwill, Beginning Balance		1,780
Purchase price allocation adjustments		6
Other movements		(3)
Goodwill, Ending Balance	1,783	1,783
International [Member]
Changes in the carrying amount of goodwill by operating segment
Goodwill, Beginning Balance	448	432
Purchase price allocation adjustments	2
Other movements	(61)
Foreign exchange	19	16
Goodwill, Ending Balance	$ 408	$ 448

Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 43

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Purchase price allocation adjustment for allocation not yet complete at the prior year end.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Reflects net changes to the recorded value of goodwill for foreign currency translation adjustments and purchase accounting adjustments needed to revise the carrying amount of goodwill to fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142

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Other increases or decreases during the reporting period in the carrying value of goodwill that are not separately disclosed.

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Goodwill (Textuals) [Abstract]

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Tax Benefit Arising On The Exercise Of Fully Vested Stock Options.

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