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v2.4.1.9

Employee Benefit Plans (Health Care Cost Trend Rates) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
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Dec. 26, 2014 | Dec. 27, 2013
Maximum [Member] |  |
Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract] |  |
Effect of a one percent increase on service and interest costs | 1 us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents / us-gaap_RangeAxis = us-gaap_MaximumMember |
Effect of a one percent increase on postretirement benefit obligation | 1 us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation / us-gaap_RangeAxis = us-gaap_MaximumMember |
Post-retirement Benefits [Member] |  |
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract] |  |
Expected rates assumed in health care costs trend rates for medical plans (in hundreds) | 4.75%us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember |
Components of Benefit Cost: Non-Medicare Eligible | 8.00%csx_DefinedBenefitPlanHealthCareCostTrendRateComponentsOfBenefitCostNonMedicareEligible / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember | 8.50%csx_DefinedBenefitPlanHealthCareCostTrendRateComponentsOfBenefitCostNonMedicareEligible / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Components of Benefit Cost: Medicare Eligible | 7.50%csx_DefinedBenefitPlanHealthCareCostTrendRateComponentsOfBenefitCostMedicareEligible / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember | 8.00%csx_DefinedBenefitPlanHealthCareCostTrendRateComponentsOfBenefitCostMedicareEligible / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Benefit Obligations: Non-Medicare Eligible | 8.00%csx_DefinedBenefitPlanHealthCareCostTrendRateBenefitObligationsNonMedicareEligible / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember | 8.00%csx_DefinedBenefitPlanHealthCareCostTrendRateBenefitObligationsNonMedicareEligible / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Benefit Obligations: Medicare Eligible | 7.50%csx_DefinedBenefitPlanHealthCareCostTrendRateBenefitObligationsMedicareEligible / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember | 7.50%csx_DefinedBenefitPlanHealthCareCostTrendRateBenefitObligationsMedicareEligible / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

X
- Definition The rate of benefit obligation related to individuals eligible for Medicare. + References No definition available. + Details
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X
- Definition The rate of benefit obligation related to individuals not eligible for Medicare. + References No definition available. + Details
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- Definition The rate of component of benefit cost related to individuals eligible for Medicare. + References No definition available. + Details
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- Definition The rate of component of benefit cost related to individuals not eligible for Medicare. + References No definition available. + Details
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- Details
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- Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (m) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (m) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
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Balance Type: | debit
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- Definition The ultimate trend rate for health care costs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
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