Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Summary of income tax benefit

Income tax expense (benefit) is summarized as follows:

	Year Ended December 31,
(In thousands)	2018			2017			2016
Current
Federal	$	(95,191	)	$	(9,531	)	$	(9,920	)
State	6,682			1,816			(1,848		)
	(88,509		)	(7,715		)	(11,768		)
Deferred
Federal	230,643			(313,938		)	(218,357		)
State	(1,040		)	(7,175		)	(12,350		)
	229,603			(321,113		)	(230,707		)
Income tax expense (benefit)	$	141,094		$	(328,828	)	$	(242,475	)

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

	Year Ended December 31,
	2018					2017					2016
(In thousands, except rates)	Amount			Rate		Amount			Rate		Amount			Rate
Computed "expected" federal income tax	$	146,609		21.00	%	$	(79,952	)	35.00	%	$	(230,860	)	35.00	%
State income tax, net of federal income tax benefit	11,850			1.70	%	(4,239		)	1.86	%	(10,888		)	1.65	%
Deferred tax adjustment related to change in overall state tax rate	(15,208		)	(2.18	)%	(48		)	0.02	%	(663		)	0.10	%
Valuation allowance	8,975			1.29	%	(505		)	0.22	%	221			(0.03	)%
Provision to return adjustments	(1,773		)	(0.25	)%	(3,242		)	1.42	%	(121		)	0.02	%
Excess stock compensation	327			0.05	%	2,965			(1.30	)%	—			—	%
Tax Act	(11,367		)	(1.63	)%	(242,875		)	106.32	%	—			—	%
Other, net	1,681			0.24	%	(932		)	0.41	%	(164		)	0.02	%
Income tax expense (benefit)	$	141,094		20.21	%	$	(328,828	)	143.95	%	$	(242,475	)	36.76	%

Schedule of deferred tax liabilities and deferred tax assets

The composition of net deferred tax liabilities is as follows:

	December 31,
(In thousands)	2018			2017
Deferred Tax Assets
Net operating losses	$	56,769		$	207,633
Alternative minimum tax credits	114,149			208,624
Foreign tax credits	3,473			3,541
Other business credits	3,380			3,524
Derivative instruments	—			6,645
Incentive compensation	17,378			15,898
Deferred compensation	5,690			6,065
Post-retirement benefits	6,799			7,265
Equity method investments	20,746			21,812
Capital loss carryforward	8,877			—
Other	2,957			492
Less: valuation allowance	(14,943		)	(16,711		)
Total	225,275			464,788
Deferred Tax Liabilities
Properties and equipment	670,704			691,818
Derivative instruments	13,168			—
Total	683,872			691,818
Net deferred tax liabilities	$	458,597		$	227,030