Income Taxes (Tables)

12 Months Ended

Dec. 31, 2024

Income Taxes [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

Income tax expense (benefit) was as follows (in millions):

	Years ended December 31,
	2024		2023		2022
Current:
Federal	$	1,052	$	1,193	$	1,468
State	202		235		284
Total current	1,254		1,428		1,752
Deferred:
Federal	299		174		88
State	64		(75)		(78)
Total deferred	363		99		10
Total	$	1,617	$	1,527	$	1,762

Schedule of Effective Income Tax Rate Reconciliation

Reconciliation of the U.S. federal statutory income tax rate to the effective tax rate was as follows:

	Years ended December 31,
	2024		2023		2022
U.S. Federal statutory income tax rate	21.0	%	21.0	%	21.0	%
State income taxes, net of federal tax benefit	3.2		1.9		1.9
Other, net	0.1		0.2		—
Effective tax rate	24.3	%	23.1	%	22.9	%

Schedule of Deferred Tax Assets and Liabilities

The components of deferred tax assets and liabilities were as follows (in millions):

	December 31, 2024		December 31, 2023
Deferred tax liabilities:
Property and equipment	$	(15,346)	$	(14,989)
Operating lease right-of-use assets	(243)		(203)
Other	(806)		(682)
Total deferred tax liabilities	(16,395)		(15,874)
Deferred tax assets:
Operating lease liabilities	239		201
Compensation and benefits	168		173
Casualty and environmental	96		102
Other	196		176
Total deferred tax assets	699		652
Net deferred tax liability	$	(15,696)	$	(15,222)

Schedule of Unrecognized Tax Benefits Roll Forward

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in millions):

	Years ended December 31,
	2024		2023		2022
Beginning balance	$	47	$	52	$	46
Additions for tax positions related to current year	8		6		11
Additions (reductions) for tax positions taken in prior years	1		(2)		—
Additions (reductions) for tax positions as a result of:
Lapse of statute of limitations	(8)		(9)		(5)
Ending balance	$	48	$	47	$	52