XML 34 R54.htm IDEA: XBRL DOCUMENT v2.4.1.9
Change in Plan Assets and Plan Assets in Excess of Less Than Projected Benefit Obligation (Detail) (CAD)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]    
Fair value at December 31 6,807us-gaap_DefinedBenefitPlanFairValueOfPlanAssets 5,872us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Pension benefits    
Defined Benefit Plan Disclosure [Line Items]    
Fair value at January 1 5,872us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
5,114us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
Actual return/(loss) on plan assets 923us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
491us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
Company contributions 362us-gaap_DefinedBenefitPlanContributionsByEmployer
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
600us-gaap_DefinedBenefitPlanContributionsByEmployer
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
Benefits paid (350)imo_DefinedBenefitPlanBenefitsPaidForFundedPlans
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
[1] (333)imo_DefinedBenefitPlanBenefitsPaidForFundedPlans
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
[1]
Fair value at December 31 6,807us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
5,872us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
Funded plans (589)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
(424)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
Unfunded plans (574)imo_UnfundedPlans
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
(574)imo_UnfundedPlans
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
Total (1,163)us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
[2] (998)us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
[2]
Other post-retirement benefits    
Defined Benefit Plan Disclosure [Line Items]    
Unfunded plans (634)imo_UnfundedPlans
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
(503)imo_UnfundedPlans
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Total (634)us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
[2] (503)us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
[2]
[1] Benefit payments for funded plans only.
[2] Fair value of assets less projected benefit obligation shown above.