Description of the Plan (Details) - EBP 004 $ in Thousands	12 Months Ended
Dec. 31, 2025 USD ($)
EBP, Description of Plan [Line Items]
ESOP, percent investment in company common stock	100.00%
Participant contribution, pretax, maximum annual compensation to total compensation, increment, percentage	1.00%
Employer contribution, noncash	$ 2,400
Disallowed reallocation period following transaction	30 days
Vested (in percentage)	100.00%
Maximum borrowing, amount	$ 50
Note receivable from participant, period preceding loan	1 year
Account balance (in percentage)	50.00%
Primary residence, borrowing term	25 years
Basis spread on variable rate	1.00%
Payment of benefits, monthly installment period	240 months
Involuntary rollover limit	$ 7
Distribution request period	180 days
Minimum
EBP, Description of Plan [Line Items]
Participant contribution, maximum annual compensation to total compensation, percentage	1.00%
General loan, borrowing term	1 year
Maximum
EBP, Description of Plan [Line Items]
Participant contribution, maximum annual compensation to total compensation, percentage	50.00%
General loan, borrowing term	5 years

EBP, ESOP, Percent Investment In Company Common Stock

No definition available.

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- Definition

EBP, Employer Contribution Vesting Percentage

+ References

No definition available.

+ Details

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- Definition

EBP, Involuntary Rollover, Distribution Request Period

+ References

No definition available.

+ Details

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- Definition

EBP, Involuntary Rollover Limit

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Note Receivable From Participant, General Loan, Borrowing Term

+ References

No definition available.

+ Details

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- Definition

EBP, Note Receivable From Participant, Period Preceding Loan

+ References

No definition available.

+ Details

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- Definition

EBP, Participant Contribution, Maximum Annual Compensation to Total Compensation, Increment, Percentage

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Maximum Contribution to Eligible Compensation, Percentage

+ References

No definition available.

+ Details

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- Definition

EBP, Participant Loan, Basis Spread On Variable Rate

+ References

No definition available.

+ Details

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Namespace Prefix:	csx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

EBP, Payment Of Benefits, Monthly Installment Period

+ References

No definition available.

+ Details

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

- Definition

EBP, Reallocations, Disallowed Reallocation Period Following Transaction

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase in net asset available for benefit from noncash contribution from employer of participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477063/962-205-45-7

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

+ Details

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Period Type:	duration

- Definition

Amount of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow to total participant account balance.

+ References

+ Details

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- Details

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- Details

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