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Income Taxes - Domestic and Foreign Components of Income Before Income Taxes (Detail) (USD $) In Millions, unless otherwise specified | 12 Months Ended
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Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010
Schedule Of Income Before Income Tax Domestic And Foreign Line Items |  |  |
Income before income taxes, Domestic | $ 1,812 | $ 1,282 | $ 727
Income before income taxes, Foreign | 1,693 | 1,640 | 1,670
Income before income taxes | $ 3,505 | $ 2,922 | $ 2,397

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- Definition Income before income taxes foreign. + References No definition available. + Details
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