Name:	csx_AssertedClaimsPercentage
Namespace Prefix:	csx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Loss Contingency, Claims Quantities [Roll Forward]

No definition available.

Name:	csx_LossContingencyClaimsQuantitiesRollForward
Namespace Prefix:	csx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Time period probable claim filings and claim values could be estimated with more certainty.

No definition available.

Name:	csx_LossContingencyEstimatePeriod
Namespace Prefix:	csx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Loss Contingency, Latency Period

No definition available.

Name:	csx_LossContingencyLatencyPeriod
Namespace Prefix:	csx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Loss Contingency, Prior Estimate, Period

No definition available.

Name:	csx_LossContingencyPriorEstimatePeriod
Namespace Prefix:	csx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The percent of loss contingency liability as of the balance sheet date which represents the cost of settling claims relating to events that have occurred but have not yet been reported as of the date of the financial statements.

No definition available.

Name:	csx_UnassertedClaimsPercentage
Namespace Prefix:	csx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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.

No definition available.

Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of loss contingency liability.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Number of claims dismissed.

No definition available.

Name:	us-gaap_LossContingencyClaimsDismissedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Number of claims settled.

No definition available.

Name:	us-gaap_LossContingencyClaimsSettledNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The total number of new claims filed pertaining to a loss contingency during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

Name:	us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Number of pending claims pertaining to a loss contingency.

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=csx_OccupationalCasualtyAndAsbestosIssuesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_AsbestosIssueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=csx_AsbestosCasualtyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: