Annual report pursuant to Section 13 and 15(d)

COMPANY-SPONSORED EMPLOYEE BENEFIT PLANS - Additional Information (Detail)

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COMPANY-SPONSORED EMPLOYEE BENEFIT PLANS - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]      
Health care cost trends, initial annual rate increase 7.50%    
Health care cost trends, an ultimate trend rate 5.00%    
Expected year when ultimate trend rate to be reached 2018    
Accumulated benefit obligation for pension plans $ 30,350 $ 23,307  
Employer contributions 917 1,436 3,240
Fair value of plan assets 25,401 22,837  
Plan assets target allocation 100.00% 100.00%  
Other Investments | Comingled Stock Funds
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2,960 3,895  
Other Investments | Private Equity and Real Estate
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2,455 2,302  
Unfunded commitments to limited partnerships 626    
Other Investments | Private Equity and Real Estate | Minimum
      
Defined Benefit Plan Disclosure [Line Items]      
Redemption notice period, lower limit 12 years    
Commitment to fund partnership equity investments period 3 years    
Other Investments | Private Equity and Real Estate | Maximum
      
Defined Benefit Plan Disclosure [Line Items]      
Redemption notice period, upper limit 18 years    
Commitment to fund partnership equity investments period 6 years    
Other Investments | Hedge Funds
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 4,191 2,743  
Redemption notice period, lower limit 2 months    
Redemption notice period, upper limit 3 months    
U.S. Postretirement Medical Benefits
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 460 174  
U.S. Postretirement Medical Benefits | Minimum
      
Defined Benefit Plan Disclosure [Line Items]      
Postretirement medical plans service minimum eligibility year 10 years    
Postretirement medical plans service minimum eligibility age 55 years    
Employee Defined Contribution Plans
      
Defined Benefit Plan Disclosure [Line Items]      
Contributions charged to expense 83 80 4
Defined Contribution Money Purchase Plans
      
Defined Benefit Plan Disclosure [Line Items]      
Contributions charged to expense 80 76 78
Pension Benefits
      
Defined Benefit Plan Disclosure [Line Items]      
Decrease in projected benefit obligation due to each basis point increase in discount rate 57    
Employer contributions 16 14  
Postretirement Medical Benefits
      
Defined Benefit Plan Disclosure [Line Items]      
Decrease in projected benefit obligation due to each basis point increase in discount rate 5    
Employer contributions 110 108  
International Pension Benefits
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 801 $ 613  
International Pension Benefits | Equity Securities
      
Defined Benefit Plan Disclosure [Line Items]      
Asset allocations for the plans, Equity securities 56.00% 55.00%  
International Pension Benefits | Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Asset allocations for the plans, Equity securities 34.00% 35.00%  
International Pension Benefits | Other
      
Defined Benefit Plan Disclosure [Line Items]      
Asset allocations for the plans, Equity securities 10.00% 10.00%