XML 97 R79.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Employee Benefit Plans - Schedule of Weighted-Average Assumptions Used (Details) | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2018 | Sep. 30, 2018 | Mar. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2018 | Dec. 31, 2017
Pension Benefits |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |
Benefit Cost for Current Plan Year |  |  |  |  | 6.75% | 6.75%
Benefit Cost for Subsequent Plan Year | 6.75% |  |  | 6.75% | 6.75% | 6.75%
Discount Rates: |  |  |  |  |  |
Service Cost for Plan Year |  |  | 4.35% | 4.26% | 3.74% | 4.26%
Interest Cost for Plan Year |  |  | 3.37% | 3.26% | 3.15% | 3.26%
Benefit Obligation at End of Plan Year | 4.24% |  |  | 3.56% | 4.24% | 3.56%
Salary Scale Inflation |  |  |  |  | 4.60% | 4.60%
Post-retirement Benefits |  |  |  |  |  |
Discount Rates: |  |  |  |  |  |
Service Cost for Plan Year | 4.14% | 3.68% | 4.20% | 4.11% | 4.14% | 4.11%
Interest Cost for Plan Year | 3.45% | 2.79% | 2.88% | 2.78% | 3.45% | 2.78%
Benefit Obligation at End of Plan Year | 3.98% |  |  | 3.34% | 3.98% | 3.34%

X
- Definition An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation. + References No definition available. + Details
Name: | csx_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationReturnOnPlanAssets
Namespace Prefix: | csx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Interest Cost, Discount Rate + References No definition available. + Details
Name: | csx_DefinedBenefitPlanAssumptionsUsedCalculatingInterestCostDiscountRate
Namespace Prefix: | csx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Service Cost, Discount Rate + References No definition available. + Details
Name: | csx_DefinedBenefitPlanAssumptionsUsedCalculatingServiceCostDiscountRate
Namespace Prefix: | csx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(3) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(2) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |