Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Components of Deferred Tax Assets and Liabilities

The components of deferred tax assets and liabilities at December 31, 2018 and 2017, are as follows:

	2018		2017
(in millions)			As Recast
DEFERRED TAX LIABILITIES:
Accelerated depreciation	$	3,395	$	3,123
Other	92		83
Total deferred tax liabilities	3,487		3,206
DEFERRED TAX ASSETS:
Construction obligation	355		318
Accrued employee benefits	329		301
Rapid rewards loyalty liability	267		338
Other	109		130
Total deferred tax assets	1,060		1,087
Net deferred tax liability	$	2,427	$	2,119

Components of the Income Tax Provision

The provision (benefit) for income taxes is composed of the following:

	2018		2017			2016
(in millions)			As Recast			As Recast
CURRENT:
Federal	$	338	$	904		$	778
State	60		72			69
Total current	398		976			847
DEFERRED:
Federal	299		200			393
State	2		2			27
Change in federal statutory tax rate	—		(1,270		)	—
Total deferred	301		(1,068		)	420
	$	699	$	(92	)	$	1,267

Income Tax Provision Reconciliation To Federal Income Tax Statutory Rate

The effective tax rate on income before income taxes differed from the federal income tax statutory rate for the following reasons:

	2018			2017			2016
(in millions)				As Recast			As Recast
Tax at statutory U.S. tax rates	$	664		$	1,143		$	1,208
State income taxes, net of federal benefit	49			50			62
Change in federal statutory tax rate	—			(1,270		)	—
Other, net	(14		)	(15		)	(3		)
Total income tax provision (benefit)	$	699		$	(92	)	$	1,267