v2.4.0.6
Debt (Fair Value of Debt) (Details) (USD $)
In Millions, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term Debt $ 10,672 $ 10,425
Long Term Debt, Fair Value Excluding Capital Leases 10,845 10,371
Debt Excluding Capital Leases 10,291 10,014
Corporate Debt Securities [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term Debt, Fair Value 6,378 6,219
Long-term Debt 5,892 5,892
Notes Payable and Other Payables excluding Leases [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term Debt, Fair Value 1,750 [1] 1,467 [1]
Long-term Debt 1,789 [1] 1,504 [1]
Loans Payable [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term Debt, Fair Value 1,644 1,615
Long-term Debt 1,634 1,646
Secured Debt [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term Debt, Fair Value 1,073 1,070
Long-term Debt $ 976 $ 972
[1] Excludes a lease that is accounted for as a failed sale-leaseback transaction under U.S. GAAP