Annual report pursuant to Section 13 and 15(d)

COMPANY-SPONSORED EMPLOYEE BENEFIT PLANS - Fair Value Measurement of Plan Assets Using Unobservable Inputs (Detail)

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COMPANY-SPONSORED EMPLOYEE BENEFIT PLANS - Fair Value Measurement of Plan Assets Using Unobservable Inputs (Detail) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Actual Return on Assets:    
Fair value of plan assets at end of year $ 25,401 $ 22,837
Fair Value, Inputs, Level 3
    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 5,125 4,314
Actual Return on Assets:    
Assets Held at End of Year 459 397
Assets Sold During the Year 6 30
Purchases 2,299 1,128
Sales (1,105) (744)
Settlements 0 0
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year 6,784 5,125
Fair Value, Inputs, Level 3 | Global Bonds
    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 80 193
Actual Return on Assets:    
Assets Held at End of Year 1 (14)
Assets Sold During the Year (3) 3
Purchases 71 57
Sales (11) (159)
Settlements 0 0
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year 138 80
Fair Value, Inputs, Level 3 | Hedge Funds
    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 2,132 1,765
Actual Return on Assets:    
Assets Held at End of Year 59 69
Assets Sold During the Year 5 22
Purchases 1,300 457
Sales (667) (181)
Settlements 0 0
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year 2,829 2,132
Fair Value, Inputs, Level 3 | Structured Products(1)
    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 948 789
Actual Return on Assets:    
Assets Held at End of Year 85 144
Assets Sold During the Year 4 5
Purchases 144 150
Sales (142) (140)
Settlements 0 0
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year 1,039 948
Fair Value, Inputs, Level 3 | Other(2)
    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 1,354 1,309
Actual Return on Assets:    
Assets Held at End of Year 163 145
Assets Sold During the Year 0 0
Purchases 184 164
Sales (285) (264)
Settlements 0 0
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year 1,416 1,354
Fair Value, Inputs, Level 3 | Other
    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 611 258
Actual Return on Assets:    
Assets Held at End of Year 151 53
Assets Sold During the Year 0 0
Purchases 600 300
Sales 0 0
Settlements 0 0
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year $ 1,362 $ 611