v2.4.0.6
Changes to Debt (Detail) (USD $)
In Millions, unless otherwise specified
 3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Debt Instrument [Line Items]    
Debt maturing within one year, beginning balance $ 4,369  
Long-term debt, beginning balance 47,618  
Total, beginning balance 51,987  
Proceeds from long-term borrowings 500  
Repayments of long-term borrowings and capital leases obligations (73) (1,828)
Increase (decrease) in short-term obligations, excluding current maturities 581 (1,734)
Other (114)  
Debt maturing within one year, ending balance 10,888  
Long-term debt, ending balance 41,993  
Total, ending balance 52,881  
Long-term Debt
    
Debt Instrument [Line Items]    
Long-term debt, beginning balance 47,618  
Proceeds from long-term borrowings 500  
Reclassifications of long-term debt (6,008)  
Other (117)  
Long-term debt, ending balance 41,993  
Debt Maturing Within One Year
    
Debt Instrument [Line Items]    
Debt maturing within one year, beginning balance 4,369  
Repayments of long-term borrowings and capital leases obligations (73)  
Increase (decrease) in short-term obligations, excluding current maturities 581  
Reclassifications of long-term debt 6,008  
Other 3  
Debt maturing within one year, ending balance $ 10,888