Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of income tax expense (benefit) from continuing operations

Income tax (benefit) expense is summarized as follows:

	Years Ended December 31,
	2018			2017			2016
	(Thousands)
Current:
Federal	$	(513,293	)	$	(89,149	)	$	(181,817	)
State	(46,218		)	(5,184		)	(22,627		)
Subtotal	(559,511		)	(94,333		)	(204,444		)
Deferred:
Federal	20,496			(1,039,769		)	(110,734		)
State	(157,496		)	(54,314		)	(47,591		)
Subtotal	(137,000		)	(1,094,083		)	(158,325		)
Total income taxes	$	(696,511	)	$	(1,188,416	)	$	(362,769	)

Schedule of reconciliation of income tax expense to amount computed at the federal statutory rate

Income tax (benefit) expense from continuing operations differed from amounts computed at the federal statutory rate of 21% for 2018 and 35% for 2017 and 2016 on pre-tax income as follows:

	Years Ended December 31,
	2018			2017			2016
	(Thousands)
Tax at statutory rate	$	(646,261	)	$	69,515		$	(312,992	)
Federal tax reform	5,288			(1,205,140		)	—
State income taxes	(251,780		)	(57,414		)	(76,043		)
Valuation allowance	88,785			10,680			23,808
Regulatory liability/asset	(276		)	10,488			—
Federal tax credits	(2,400		)	(34,956		)	(4,539		)
Goodwill impairment	111,470			—			—
Other	(1,337		)	18,411			6,997
Income tax (benefit) expense	$	(696,511	)	$	(1,188,416	)	$	(362,769	)
Effective tax rate	22.6		%	(598.4		)%	40.6		%

Schedule of reconciliation of the beginning and ending amount of reserve for uncertain tax positions(excluding interest and penalties)

The following table reconciles the beginning and ending amount of reserve for uncertain tax positions (excluding interest and penalties): 

	2018			2017			2016
	(Thousands)
Balance at January 1	$	301,558		$	252,434		$	259,301
Additions based on tax positions related to current year	8,459			50,469			23,978
Additions for tax positions of prior years	14,396			8,978			20,336
Reductions for tax positions of prior years	(9,134		)	(10,323		)	(51,181		)
Balance at December 31	$	315,279		$	301,558		$	252,434

Summary of source and tax effects of temporary differences between financial reporting and tax bases of assets and liabilities

The following table summarizes the source and tax effects of temporary differences between financial reporting and tax bases of assets and liabilities:

	As of December 31,
	2018			2017
	(Thousands)
Deferred income taxes:
Total deferred income tax assets	$	(901,377	)	$	(1,112,514	)
Total deferred income tax liabilities	2,724,758			3,002,476
Total net deferred income tax liabilities	1,823,381			1,889,962
Total deferred income tax liabilities (assets):
Drilling and development costs expensed for income tax reporting	1,469,320			2,074,091
Tax depreciation in excess of book depreciation	904,030			644,590
Investment in Equitrans Midstream	(10,359		)	—
Incentive compensation and deferred compensation plans	(24,682		)	(43,822		)
Net operating loss carryforwards	(429,983		)	(564,180		)
Alternative minimum tax credit carryforward	(308,727		)	(435,190		)
Federal tax credits	(37,710		)	(50,341		)
Unrealized (losses) gains	(28,096		)	21,403
Interest disallowance limitation	(35,358		)	—
Other	(26,462		)	(18,981		)
Total excluding valuation allowances	1,471,973			1,627,570
Valuation allowances	351,408			262,392
Total net deferred income tax liabilities	$	1,823,381		$	1,889,962