Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Schedule of componenets of provision for income taxes

The provision for income taxes consists of the following:

	For the Years Ended December 31,
	2016			2015			2014
	(in thousands)
Current portion of income tax expense
Federal	$	2,932		$	—		$	—
State	1,539			1,571			868
Deferred portion of income tax expense (benefit)	(448,643		)	(276,722		)	397,780
Total income tax expense (benefit)	$	(444,172	)	$	(275,151	)	$	398,648
Effective tax rate	37.0		%	38.1		%	37.4		%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

The components of the net deferred income tax liabilities are as follows:

	As of December 31,
	2016			2015
	(in thousands)
Deferred tax liabilities:
Oil and gas properties	$	518,394		$	854,029
Derivative asset	—			179,543
Other	7,733			1,233
Total deferred tax liabilities	526,127			1,034,805
Deferred tax assets:
Federal and state tax net operating loss carryovers	151,343			244,942
Derivative liability	31,349			—
Stock compensation	10,083			14,529
Credit carryover	12,448			6,952
Other liabilities	10,567			20,497
Total deferred tax assets	215,790			286,920
Valuation allowance	(5,335		)	(10,394		)
Net deferred tax assets	210,455			276,526
Total net deferred tax liabilities	$	315,672		$	758,279
Current federal income tax refundable	$	644		$	5,378
Current state income tax refundable	$	—		$	65
Current state income tax payable	$	1,181		$	—

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

Federal income tax expense differs from the amount that would be provided by applying the statutory United States federal income tax rate to income before income taxes primarily due to the effect of state income taxes, changes in valuation allowances, R&D credits, and accumulated impacts of other smaller permanent differences, reported as follows:

	For the Years Ended December 31,
	2016			2015			2014
	(in thousands)
Federal statutory tax expense (benefit)	$	(420,671	)	$	(253,001	)	$	372,644
Increase (decrease) in tax resulting from:
State tax expense (benefit) (net of federal benefit)	(17,549		)	(21,583		)	21,350
Change in valuation allowance	(5,059		)	3,148			2,245
Research and development credit	—			(1,971		)	—
Other	(893		)	(1,744		)	2,409
Income tax expense (benefit)	$	(444,172	)	$	(275,151	)	$	398,648

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

The total amount recorded for unrecognized tax benefits is presented below:

	For the Years Ended December 31,
	2016			2015		2014
	(in thousands)
Beginning balance	$	2,782		$	1,582	$	2,358
Additions for tax positions of prior years	9			1,200		140
Settlements	(2,345		)	—		(916		)
Ending balance	$	446		$	2,782	$	1,582