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Pension and Other Postretirement Benefit Plans - Fair Values of Other Postretirement Benefit Plan Assets (Detail) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2013
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Dec. 31, 2012
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Dec. 31, 2011
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|---|---|---|---|
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Significant Unobservable Inputs (Level 3) [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | $ 622 | $ 692 | $ 637 |
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Other Postretirement Benefit Plans, Defined Benefit [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 1,913 | 1,760 | 1,628 |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 67 | 75 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Developed markets equities, Investment funds [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 721 | 538 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Emerging markets equities, Investment funds [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 131 | 112 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Fixed income obligations, Investment funds [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 17 | 26 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Developed markets, Equity securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 199 | 139 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Government and agency obligations, Fixed income securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 257 | 298 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Corporate obligations, Fixed income securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 281 | 310 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Mortgage and asset-backed securities, Fixed income securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 219 | 238 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Other Fixed Income Securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 21 | 24 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 339 | 243 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Cash and Cash Equivalents [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 47 | 27 | |
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Other Postretirement Benefit 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 | 54 | 37 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Emerging markets equities, Investment funds [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 36 | 37 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Fixed income obligations, Investment funds [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 3 | 3 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Developed markets, Equity securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 199 | 139 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Government and agency obligations, Fixed income securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 0 | 0 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Corporate obligations, Fixed income securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 0 | 0 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Mortgage and asset-backed securities, Fixed income securities [Member]
|
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 0 | 0 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Other Fixed Income Securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 0 | 0 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 1,574 | 1,517 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Cash and Cash Equivalents [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 20 | 48 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Developed markets equities, Investment funds [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 667 | 501 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Emerging markets equities, Investment funds [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 95 | 75 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fixed income obligations, Investment funds [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 14 | 23 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Developed markets, Equity securities [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 0 | 0 | |
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Other Postretirement Benefit 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 | 257 | 298 | |
|
Other Postretirement Benefit 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 | 281 | 310 | |
|
Other Postretirement Benefit 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 | 219 | 238 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other Fixed Income Securities [Member]
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|||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 21 | 24 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 0 | 0 | |
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Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Cash and Cash Equivalents [Member]
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|||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | 0 | 0 | |
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Other Postretirement Benefit 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 | |
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Other Postretirement Benefit 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 | |
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Other Postretirement Benefit 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 | |
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Other Postretirement Benefit 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 | |
|
Other Postretirement Benefit 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 | |
|
Other Postretirement Benefit 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 | |
|
Other Postretirement Benefit 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 | |
|
Other Postretirement Benefit Plans, Defined Benefit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other Fixed Income Securities [Member]
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|||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Fair Value of Plan Assets | $ 0 | $ 0 |