Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Taxes [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

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

	Years ended December 31,
	2022		2021		2020
Current:
Federal	$	1,468	$	1,173	$	1,111
State	284		252		231
Total current	1,752		1,425		1,342
Deferred:
Federal	88		422		256
State	(78)		24		33
Total deferred	10		446		289
Total	$	1,762	$	1,871	$	1,631

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,
	2022		2021		2020
U.S. Federal statutory income tax rate	21.0	%	21.0	%	21.0	%
State income taxes, net of federal tax benefit	1.9		2.8		3.0
Effective tax rate	22.9	%	23.8	%	24.0	%

Schedule of Deferred Tax Assets and Liabilities

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

	December 31, 2022		December 31, 2021
Deferred tax liabilities:
Property and equipment	$	(14,895)	$	(14,953)
Operating lease right-of-use assets	(233)		(314)
Other	(634)		(621)
Total deferred tax liabilities	(15,762)		(15,888)
Deferred tax assets:
Operating lease liabilities	232		315
Compensation and benefits	166		202
Casualty and environmental	97		105
Other	157		110
Total deferred tax assets	652		732
Net deferred tax liability	$	(15,110)	$	(15,156)

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,
	2022		2021		2020
Beginning balance	$	46	$	41	$	46
Additions for tax positions related to current year	11		9		7
Additions (reductions) for tax positions taken in prior years	—		—		(2)
Additions (reductions) for tax positions as a result of:
Settlements	—		—		(3)
Lapse of statute of limitations	(5)		(4)		(7)
Ending balance	$	52	$	46	$	41