Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Summary of income tax benefit

Income tax benefit is summarized as follows:

	Year Ended December 31,
(In thousands)	2017			2016			2015
Current
Federal	$	(9,531	)	$	(9,920	)	$	983
State	1,816			(1,848		)	(1,397		)
	(7,715		)	(11,768		)	(414		)
Deferred
Federal	(313,938		)	(218,357		)	(72,869		)
State	(7,175		)	(12,350		)	(99		)
	(321,113		)	(230,707		)	(72,968		)
Income tax benefit	$	(328,828	)	$	(242,475	)	$	(73,382	)

Schedule of reconciliation of actual provision for income taxes and provision for income taxes computed by applying the statutory federal income tax rate

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

	Year Ended December 31,
	2017					2016					2015
(In thousands, except rates)	Amount			Rate		Amount			Rate		Amount			Rate
Computed "expected" federal income tax	$	(79,952	)	35.00	%	$	(230,860	)	35.00	%	$	(65,546	)	35.00	%
State income tax, net of federal income tax benefit	(4,239		)	1.86	%	(10,888		)	1.65	%	(3,152		)	1.68	%
Deferred tax adjustment related to change in overall state tax rate	(48		)	0.02	%	(663		)	0.10	%	2,822			(1.51	)%
Valuation allowance	(505		)	0.22	%	221			(0.03	)%	187			(0.10	)%
Provision to return adjustments	(3,242		)	1.42	%	(121		)	0.02	%	(6,326		)	3.38	%
Excess stock compensation	2,965			(1.30	)%	—			—	%	—			—	%
Tax Act	(242,875		)	106.32	%	—			—	%	—			—	%
Other, net	(932		)	0.41	%	(164		)	0.02	%	(1,367		)	0.73	%
Income tax benefit	$	(328,828	)	143.95	%	$	(242,475	)	36.76	%	$	(73,382	)	39.18	%

Schedule of deferred tax liabilities and deferred tax assets

The composition of net deferred tax liabilities is as follows:

	December 31,
(In thousands)	2017			2016
Deferred Tax Assets
Net operating losses	$	207,633		$	352,001
Alternative minimum tax credits	208,624			218,773
Foreign tax credits	3,541			3,816
Other business credits	3,524			—
Derivative instruments	6,645			13,771
Incentive compensation	15,898			22,852
Deferred compensation	6,065			8,217
Post-retirement benefits	7,265			13,865
Equity method investments	21,812			—
Other	492			2,743
Less: valuation allowance	(16,711		)	(5,186		)
Total	464,788			630,852
Deferred Tax Liabilities
Properties and equipment	691,818			1,207,545
Equity method investments	—			2,754
Total	691,818			1,210,299
Net deferred tax liabilities	$	227,030		$	579,447