v2.4.0.6
Fair Value Measurements (Schedule Of Carrying Value And Fair Value Measurement Information For Financial Assets And Liabilities) (Details) (USD $)
In Millions, unless otherwise specified
Jun. 30, 2012
Dec. 31, 2011
Jun. 30, 2011
Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, assets $ 1,005 $ 680    
Derivatives, liabilities (45) (82)    
Debt (19) (85) (104) (144)
Carrying Amount [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Cash equivalents 5,841 5,123    
Debt (10,603) (9,780)    
Total Fair Value [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Cash equivalents 5,841 5,123    
Debt (12,260) (11,380)    
Level 1 Inputs [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Cash equivalents 850 929    
Level 2 Inputs [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Cash equivalents 4,991 4,194    
Debt (12,241) (11,295)    
Level 3 Inputs [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Debt (19) (85)    
Short-Term Investments [Member] | Carrying Amount [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Investments 944 1,503    
Short-Term Investments [Member] | Total Fair Value [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Investments 944 1,503    
Short-Term Investments [Member] | Level 1 Inputs [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Investments 300 201    
Short-Term Investments [Member] | Level 2 Inputs [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Investments 644 1,302    
Long-Term Investments [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Investments 69 84 93 94
Long-Term Investments [Member] | Carrying Amount [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Investments 69 84    
Long-Term Investments [Member] | Total Fair Value [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Investments 69 84    
Long-Term Investments [Member] | Level 3 Inputs [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Investments 69 84    
Commodity Derivatives [Member] | Carrying Amount [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, assets 968 628    
Derivatives, liabilities (37) (82)    
Commodity Derivatives [Member] | Total Fair Value [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, assets 968 628    
Derivatives, liabilities (37) (82)    
Commodity Derivatives [Member] | Level 2 Inputs [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, assets 968 628    
Derivatives, liabilities (37) (82)    
Interest Rate Derivatives [Member] | Carrying Amount [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, assets 37 52    
Interest Rate Derivatives [Member] | Total Fair Value [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, assets 37 52    
Interest Rate Derivatives [Member] | Level 2 Inputs [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, assets 37 52    
Foreign Exchange Derivatives [Member] | Carrying Amount [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, liabilities (8)      
Foreign Exchange Derivatives [Member] | Total Fair Value [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, liabilities (8)      
Foreign Exchange Derivatives [Member] | Level 2 Inputs [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivatives, liabilities $ (8)