Income Taxes

Income tax benefit is summarized as follows:



	Year Ended December 31,
(In thousands)	2016			2015			2014
Current
Federal	$	(9,920	)	$	983		$	44,887
State	(1,848		)	(1,397		)	(4,387		)
	(11,768		)	(414		)	40,500
Deferred
Federal	(218,357		)	(72,869		)	(32,375		)
State	(12,350		)	(99		)	(80,192		)
	(230,707		)	(72,968		)	(112,567		)
Income tax benefit	$	(242,475	)	$	(73,382	)	$	(72,067	)

Income tax benefit was different than the amounts computed by applying the statutory federal income tax rate as follows:



	Year Ended December 31,
	2016					2015					2014
(In thousands, except rates)	Amount			Rate		Amount			Rate		Amount			Rate
Computed "expected" federal income tax	$	(230,860	)	35.00	%	$	(65,546	)	35.00	%	$	11,341		35.00	%
State income tax, net of federal income tax benefit	(10,888		)	1.65	%	(3,152		)	1.68	%	903			2.79	%
Deferred tax adjustment related to change in overall state tax rate	(663		)	0.10	%	2,822			(1.51	)%	(86,956		)	(268.36	)%
Valuation allowance	221			(0.03	)%	187			(0.10	)%	3,977			12.27	%
Uncertain tax positions	—			—	%	—			—	%	(1,974		)	(6.09	)%
Provision to return adjustments	(121		)	0.02	%	(6,326		)	3.38	%	(791		)	(2.44	)%
Other, net	(164		)	0.02	%	(1,367		)	0.73	%	1,433			4.42	%
Income tax benefit	$	(242,475	)	36.76	%	$	(73,382	)	39.18	%	$	(72,067	)	(222.41	)%

In 2016, the Company's overall effective tax rate decreased compared to 2015, primarily due to larger provision-to-return adjustments in 2015 compared to 2016. The overall effective tax rate was significantly lower in 2014 due to a change in the effective state income tax rate based on updated state apportionment factors in the states in which the Company operates. For state income tax purposes, the Company must estimate the respective amounts of future earnings that are subject to income tax in the various states in which the Company operates. These estimates may change based on a variety of factors, including, but not limited to, the composition and location of the Company’s asset base, its employees, and its customers. The 2014 decrease in the Company’s state apportionment factors was primarily driven by a shift in the sourcing of revenues based on the location of customers to whom the Company ultimately sells its natural gas in the northeast United States. The 2014 decrease in the effective state income tax rate significantly affected the Company’s estimated net state deferred tax liabilities reflected in its Consolidated Balance Sheet, resulting in an income tax benefit of approximately $87.0 million that was reflected in the Company’s provision for income taxes in 2014.

The composition of net deferred tax liabilities is as follows:



	December 31,
(In thousands)	2016			2015
Deferred Tax Assets
Net operating losses	$	352,001		$	223,402
Alternative minimum tax credits	218,773			228,693
Foreign tax credits	3,816			3,837
Derivative instruments	13,771			—
Incentive compensation	22,852			22,509
Deferred compensation	8,217			7,869
Post-retirement benefits	13,865			13,556
Other	2,743			2,905
Less: valuation allowance	(5,186		)	(4,965		)
Total	630,852			497,806
Deferred Tax Liabilities
Properties and equipment	1,207,545			1,303,840
Equity method investments	2,754			1,202
Total	1,210,299			1,305,042
Net deferred tax liabilities	$	579,447		$	807,236

As of December 31, 2016, the Company had alternative minimum tax credit carryforwards of $218.8 million, which do not expire and can be used to offset regular income taxes in future years to the extent that regular income taxes exceed the alternative minimum tax in any such year. The Company also had gross net operating loss carryforwards of $1.0 billion and $636.1 million for federal and state reporting purposes, respectively, the majority of which will expire between 2022 and 2036. The Company has $4.8 million of state valuation allowances, and believes it is more likely than not that the remainder of the deferred tax benefits will be utilized prior to their expiration. Tax benefits related to employee stock-based compensation included in net operating loss carryforwards but not reflected in deferred tax assets as of December 31, 2016 are approximately $120.3 million.

Unrecognized Tax Benefits

A reconciliation of unrecognized tax benefits is as follows:



	Year Ended December 31,
(In thousands)	2016		2015		2014
Balance at beginning of year	$	663	$	663	$	3,700
Additions based on tax provisions related to the current year	—		—		—
Additions for tax positions of prior years	—		—		—
Reductions for tax positions of prior years	—		—		(3,037		)
Settlements	—		—		—
Balance at end of year	$	663	$	663	$	663

During 2013, the Company recorded unrecognized tax benefits of $3.7 million based on the allocation of certain gains associated with its divestitures for purposes of computing state income taxes. These benefits were reduced during 2014 by $3.0 million based on changes to the Company's state tax rates. There was no change to the Company's unrecognized tax benefits during 2016 or 2015. If recognized, the net tax benefit of $0.7 million would not have a material effect on the Company's effective tax rate.

The Company files income tax returns in the U.S. federal, various states and other jurisdictions. The Company is no longer subject to examinations by state authorities before 2012 or by federal authorities before 2013. The Company is not currently under examination by the Internal Revenue Service. The Company believes that appropriate provisions have been made for all jurisdictions and all open years, and that any assessment on these filings will not have a material impact on the Company's financial position, results of operations or cash flows.