Goodwill and Other Intangible Assets Weighted-average useful lives assigned to finite-lived intangible assets acquired in business combinations (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010 years
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Amount	$ 241	$ 894
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life, in years	9	13
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Amount	187	786
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life, in years	9	14
Trademarks and technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Amount	49	94
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life, in years	5	8
Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Amount	$ 5	$ 14
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life, in years	15	9