Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Schedule of componenets of provision for income taxes

The provision for income taxes consists of the following:



	For the Years Ended December 31,
	2014			2013			2012
	(in thousands)
Current portion of income tax expense
Federal	$	—		$	—		$	—
State	868			2,121			370
Deferred portion of income tax expense (benefit)	397,780			105,555			(29,638		)
Total income tax expense (benefit)	$	398,648		$	107,676		$	(29,268	)
Effective tax rate	37.4		%	38.6		%	35.0		%

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,
	2014			2013
	(in thousands)
Deferred tax liabilities:
Oil and gas properties	$	1,029,424		$	768,463
Derivative asset	220,437			9,529
Other	4,475			1,245
Total deferred tax liabilities	1,254,336			779,237
Deferred tax assets:
Federal and state tax net operating loss carryovers	184,447			91,788
Stock compensation	16,763			18,820
Other long-term liabilities	16,301			13,341
Net Profits Plan liability	9,414			20,913
Total deferred tax assets	226,925			144,862
Valuation allowance	(7,246		)	(5,001		)
Net deferred tax assets	219,679			139,861
Total net deferred tax liabilities	1,034,657			639,376
Less: current deferred income tax liabilities	(152,082		)	(172		)
Add: current deferred income tax assets	9,106			10,921
Non-current net deferred tax liabilities	$	891,681		$	650,125
Current federal income tax refundable	$	4,734		$	4,630
Current state income tax refundable	$	—		$	—
Current state income tax payable	$	25		$	1,460

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, percentage depletion, R&D credits, and other permanent differences, as follows:



	For the Years Ended December 31,
	2014		2013			2012
	(in thousands)
Federal statutory tax expense (benefit)	$	372,644	$	97,514		$	(29,231	)
Increase (decrease) in tax resulting from:
State tax expense (benefit) (net of federal benefit)	21,350		9,400			(992		)
Research and development credit	—		—			(970		)
Change in valuation allowance	2,245		(314		)	1,524
Other	2,409		1,076			401
Income tax expense (benefit)	$	398,648	$	107,676		$	(29,268	)

Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table Text Block]

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



	For the Years Ended December 31,
	2014			2013		2012
	(in thousands)
Beginning balance	$	2,358		$	2,278	$	1,961
Additions for tax positions of prior years	140			80		317
Settlements	(916		)	—		—
Ending balance	$	1,582		$	2,358	$	2,278