Employee Benefit Plans - Schedule of Participants (Details)	Jan. 01, 2024 employee
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Active Employees	2,314
Retirees and Beneficiaries	11,105
Terminated Vested and Other	3,327
Total	16,746

The total Retirees and Beneficiaries employees who are participants to pension and post retirement plans as of the balance sheet date.

No definition available.

Name:	csx_RetireesAndBeneficiariesParticipating
Namespace Prefix:	csx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant