| 
           Location on the Balance Sheet of Derivative Assets and Liabilities (Detail) (Fair Value, Inputs, Level 2, USD $) 
        In Millions, unless otherwise specified  | 
        
           Mar. 31, 2012 
         | 
        
           Dec. 31, 2011 
         | 
      
|---|---|---|
| Asset Derivatives | ||
| Asset Derivatives | $ 543 | $ 649 | 
| Derivative Liabilities [Abstract] | ||
| Liability Derivatives | 166 | 208 | 
| 
           Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets 
         | 
        ||
| Asset Derivatives | ||
| Asset Derivatives | 85 | 164 | 
| 
           Designated as Hedging Instrument | Foreign Exchange Contracts | Other noncurrent assets 
         | 
        ||
| Asset Derivatives | ||
| Asset Derivatives | 23 | 0 | 
| 
           Designated as Hedging Instrument | Foreign Exchange Contracts | Other non-current liabilities 
         | 
        ||
| Derivative Liabilities [Abstract] | ||
| Liability Derivatives | 143 | 185 | 
| 
           Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets 
         | 
        ||
| Asset Derivatives | ||
| Asset Derivatives | 365 | 401 | 
| 
           Designated as Hedging Instrument | Interest Rate Contracts | Other current liabilities 
         | 
        ||
| Derivative Liabilities [Abstract] | ||
| Liability Derivatives | 9 | 0 | 
| 
           Designated as Hedging Instrument | Interest Rate Contracts | Other non-current liabilities 
         | 
        ||
| Derivative Liabilities [Abstract] | ||
| Liability Derivatives | 12 | 13 | 
| 
           Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets 
         | 
        ||
| Asset Derivatives | ||
| Asset Derivatives | 0 | 2 | 
| 
           Not Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets 
         | 
        ||
| Asset Derivatives | ||
| Asset Derivatives | 70 | 82 | 
| 
           Not Designated as Hedging Instrument | Interest Rate Contracts | Other non-current liabilities 
         | 
        ||
| Derivative Liabilities [Abstract] | ||
| Liability Derivatives | $ 2 | $ 10 |