Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Our income tax provision consisted of the following:



	Year Ended December 31,
(in millions)	2018			2017			2016
Current tax (provision) benefit:
Federal	$	187		$	(4	)	$	—
State and local	(26		)	5			(28		)
International	(13		)	(54		)	(12		)
Deferred tax provision:
Federal	(1,226		)	(2,093		)	(1,990		)
State and local	(138		)	(149		)	(128		)
Income tax provision	$	(1,216	)	$	(2,295	)	$	(2,158	)

Schedule of effective income tax rate reconciliation

The following table presents the principal reasons for the difference between the effective tax rate and the U.S. federal statutory income tax rate:



	Year Ended December 31,
	2018		2017		2016
U.S. federal statutory income tax rate	21.0	%	35.0	%	35.0	%
State taxes, net of federal benefit	2.5		1.8		1.8
Foreign tax rate differential	0.1		(2.2	)	(2.1	)
Tax Cuts and Jobs Act adjustment	(0.5	)	7.2		—
Other	0.5		—		(0.7	)
Effective income tax rate	23.6	%	41.8	%	34.0	%

Schedule of deferred taxes

The following table shows significant components of our deferred tax assets and liabilities:



	December 31,
(in millions)	2018			2017
Deferred tax assets:
Net operating loss carryforwards	$	674		$	1,297
Pension, postretirement and other benefits	2,435			2,544
Alternative minimum tax credit carryforward	189			379
Deferred revenue	1,620			1,416
Operating lease liabilities	1,579			—
Other	357			728
Valuation allowance	(13		)	(15		)
Total deferred tax assets	$	6,841		$	6,349
Deferred tax liabilities:
Depreciation	$	4,185		$	3,847
Operating lease right-of-use assets	1,388			—
Intangible assets	1,052			1,043
Other	137			105
Total deferred tax liabilities	$	6,762		$	4,995

Net deferred tax assets⁽¹⁾	$	79		$	1,354

⁽¹⁾

At December 31, 2018, the net deferred tax assets of $79 million included $242 million of net state deferred tax assets, which are recorded in deferred income taxes, net, and $163 million of net federal deferred tax liabilities, which are recorded in other noncurrent liabilities.