Components of Deferred Tax Assets / (Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred Tax Liabilities, Property and Equipment	$ (15,346)	$ (14,989)
Deferred Tax Liabilities, Operating Lease Right-Of-Use-Assets	(243)	(203)
Deferred Tax Liabilities, Other	(806)	(682)
Deferred Tax Liabilities, Gross	(16,395)	(15,874)
Deferred Tax Assets, Operating Lease Liabilities	239	201
Deferred Tax Assets, Compensation and Benefits	168	173
Deferred Tax Assets, Casualty and environmental	96	102
Deferred Tax Assets, Other	196	176
Total Deferred Tax Assets	699	652
Deferred Tax Liabilities, Net	$ (15,696)	$ (15,222)