v2.4.0.6

Other Financial Information (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Segment Reporting Information [Line Items] |  |  |
Pretax interest expense included in discontinued operations and relates to short- and long-term debt included in the separation of the Downstream Business | $ 18 | $ 20 | $ 22

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