| 
           QUARTERLY INFORMATION (unaudited) - Additional Information (Detail) (USD $) 
        In Millions, except Per Share data, unless otherwise specified  | 
        3 Months Ended | |||
|---|---|---|---|---|
| 
           Dec. 31, 2012 
         | 
        
           Sep. 30, 2012 
         | 
        
           Dec. 31, 2011 
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           Jun. 30, 2011 
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      |
| Quarterly Financial Information [Line Items] | ||||
| Increase (decrease) in net income | $ 3,023 | $ 527 | $ 20 | |
| Increase (decrease) in basic and diluted earnings per share | $ 3.16 | $ 0.54 | $ 0.02 | |
| Impact of pension mark-to-market | 4,831 | 827 | ||
| 
           U.S. Domestic Package 
         | 
        ||||
| Quarterly Financial Information [Line Items] | ||||
| Increase (decrease) in operating profit | 896 | |||
| Increase (decrease) in net income | 559 | |||
| Increase (decrease) in basic and diluted earnings per share | $ 0.58 | |||
| Gain (loss) on sale of real estate | 15 | |||
| Impact of pension mark-to-market | 3,177 | 479 | ||
| 
           International Package 
         | 
        ||||
| Quarterly Financial Information [Line Items] | ||||
| Impact of pension mark-to-market | 941 | 171 | ||
| 
           Supply Chain & Freight 
         | 
        ||||
| Quarterly Financial Information [Line Items] | ||||
| Gain (loss) on sale of real estate | 48 | |||
| Impact of pension mark-to-market | $ 713 | $ 177 | ||
| X | ||||||||||
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- Definition 
          Increase Decrease in Earnings Per Share Basic and Diluted No definition available. 
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| X | ||||||||||
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- Definition 
          Increase (Decrease) In Net Income Loss No definition available. 
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| X | ||||||||||
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- Definition 
          Increase (Decrease) in Operating Profit No definition available. 
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| X | ||||||||||
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- Definition 
          Mark To Market Activities, Net No definition available. 
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| X | ||||||||||
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- Details 
          
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| X | ||||||||||
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- Definition 
          The net gain (loss) resulting from sales and other disposals of other real estate owned, increases (decreases) in the valuation allowance for foreclosed real estate, and write-downs of other real estate owned after acquisition or physical possession. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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