2.2.0.7 false One-Percentage Point Change in Assumed Health Care Cost Trend Rates (Detail) (USD $) 159 - Disclosure - One-Percentage Point Change in Assumed Health Care Cost Trend Rates (Detail) true false In Millions false false 1 USD false false iso4217_USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 pure Standard http://www.xbrl.org/2003/instance pure 0 shares Standard http://www.xbrl.org/2003/instance shares 0 iso4217_USD_per_shares Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 $ 5 3 us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 6 4 us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 true true false false 63000000 63 false false false xbrli:monetaryItemType monetary The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs. (For purposes of this disclosure, all other assumptions shall be held constant, and the effects shall be measured based on the substantive plan that is the basis for the accounting.) Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph m false 7 4 us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -50000000 -50 false false false xbrli:monetaryItemType monetary The effect of a one-percentage- point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs. (For purposes of this disclosure, all other assumptions shall be held constant, and the effects shall be measured based on the substantive plan that is the basis for the accounting.) Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph m false 8 4 us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 718000000 718 false false false xbrli:monetaryItemType monetary The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits. (For purposes of this disclosure, all other assumptions shall be held constant, and the effects shall be measured based on the substantive plan that is the basis for the accounting.) Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph m false 9 4 us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 true true false false -577000000 -577 false false false xbrli:monetaryItemType monetary The effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits. (For purposes of this disclosure, all other assumptions shall be held constant, and the effects shall be measured based on the substantive plan that is the basis for the accounting.) Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph m false 1 5 false Millions UnKnown UnKnown false true