| Intangible Assets (Narrative) (Details) (USD $) In Millions, unless otherwise specified | 6 Months Ended | |
|---|---|---|
| Jun. 30, 2012 | Jun. 30, 2011 | |
| Goodwill and Intangible Assets Disclosure [Abstract] | ||
| Amortization expense for intangible assets with finite useful lives | $ 217 | $ 221 | 
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- Definition Aggregate amount of intangible asset amortization recognized as expense during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
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- Details 
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