Other Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Defined Benefit Plan Disclosure [Line Items]
Long-term advances from Conrail	$ 534	$ 534
Defined benefit plan, obligations	255	252
Non-current operating lease liability	148	191
Deferred compensation	78	90
Non-current Eastern Ohio incident liability	56	103
Other	286	228
Total	1,723	1,760
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, obligations	255	252
Casualty and other claims	241	229
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, obligations	$ 125	$ 133