v2.4.0.6
Debt (Debt) (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Debt Instrument [Line Items]    
Long-term Debt $ 10,777 $ 10,750
Debt, Current 144 115
Long-term Debt, Excluding Current Maturities (10,633) (10,635)
Corporate Debt Securities [Member]
   
Debt Instrument [Line Items]    
Long-term Debt 5,304 5,303
Notes Payable, Other Payables [Member]
   
Debt Instrument [Line Items]    
Long-term Debt 2,456 2,463
Loans Payable [Member]
   
Debt Instrument [Line Items]    
Long-term Debt 1,826 1,789
Secured Debt [Member]
   
Debt Instrument [Line Items]    
Long-term Debt 980 978
Capital Lease Obligations [Member]
   
Debt Instrument [Line Items]    
Long-term Debt $ 211 $ 217