v2.4.0.8
Pension and Other Postretirement Benefit Plans - Fair Values of Pension Plan Assets (Detail) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Significant Unobservable Inputs (Level 3) [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets $ 622 $ 692 $ 637
Significant Unobservable Inputs (Level 3) [Member] | Insurance contracts, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 540 496 428
Pension Plans, Defined Benefit [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 17,435 15,349 12,481
Pension Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 335 729  
Pension Plans, Defined Benefit [Member] | Developed markets equities, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 8,451 6,669  
Pension Plans, Defined Benefit [Member] | Emerging markets equities, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1,199 892  
Pension Plans, Defined Benefit [Member] | Government and agency obligations, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1,473 999  
Pension Plans, Defined Benefit [Member] | Corporate obligations, Investment Funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 265 260  
Pension Plans, Defined Benefit [Member] | Fixed income obligations, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 162 220  
Pension Plans, Defined Benefit [Member] | Real estate, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 110 [1] 159 [1]  
Pension Plans, Defined Benefit [Member] | Developed markets, Equity securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 2,546 2,277  
Pension Plans, Defined Benefit [Member] | Government and agency obligations, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1,098 1,054  
Pension Plans, Defined Benefit [Member] | Corporate obligations, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 741 1,008  
Pension Plans, Defined Benefit [Member] | Mortgage and asset backed-securities, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 299 269  
Pension Plans, Defined Benefit [Member] | Insurance contracts, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 668 [2] 613 [2]  
Pension Plans, Defined Benefit [Member] | Other, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 87 108  
Pension Plans, Defined Benefit [Member] | Assets [Member] | Derivatives, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1 162  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 4,110 3,688  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Cash and Cash Equivalents [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 88 142  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Developed markets equities, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 808 683  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Emerging markets equities, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 163 121  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Government and agency obligations, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 293 279  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Corporate obligations, Investment Funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 188 166  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Fixed income obligations, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 17 14  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Real estate, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 4 [1] 4 [1]  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Developed markets, Equity securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 2,546 2,277  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Government and agency obligations, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 2 2  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Corporate obligations, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Mortgage and asset backed-securities, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Insurance contracts, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 [2] 0 [2]  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Other, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Assets [Member] | Derivatives, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1 0  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 12,703 10,969  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Cash and Cash Equivalents [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 247 587  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Developed markets equities, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 7,643 5,986  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Emerging markets equities, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1,036 771  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Government and agency obligations, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1,180 720  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate obligations, Investment Funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 77 94  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fixed income obligations, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 145 206  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Real estate, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 57 [1] 14 [1]  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Developed markets, Equity securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Government and agency obligations, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1,096 1,052  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate obligations, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 741 1,008  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage and asset backed-securities, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 299 269  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Insurance contracts, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 128 [2] 117 [2]  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 54 53  
Pension Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Assets [Member] | Derivatives, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 162  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 622 692  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Cash and Cash Equivalents [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Developed markets equities, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Emerging markets equities, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Government and agency obligations, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Corporate obligations, Investment Funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed income obligations, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Real estate, Investment funds [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 49 [1] 141 [1]  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Developed markets, Equity securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Government and agency obligations, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Corporate obligations, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage and asset backed-securities, Fixed income securities [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Insurance contracts, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 540 [2] 496 [2]  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 33 55  
Pension Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Assets [Member] | Derivatives, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Liability [Member] | Derivatives, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 70  
Pension Plans, Defined Benefit [Member] | Liability [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Derivatives, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 0  
Pension Plans, Defined Benefit [Member] | Liability [Member] | Significant Other Observable Inputs (Level 2) [Member] | Derivatives, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0 70  
Pension Plans, Defined Benefit [Member] | Liability [Member] | Significant Unobservable Inputs (Level 3) [Member] | Derivatives, Other investments [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets $ 0 $ 0  
[1] The plans’ Level 3 investments in real estate funds are generally valued by market appraisals of the underlying investments in the funds.
[2] The plans’ Level 3 investments in insurance contracts are generally valued using a crediting rate that approximates market returns and invest in underlying securities whose market values are unobservable and determined using pricing models, discounted cash flow methodologies, or similar techniques.