Income Taxes

The following table summarizes our provision for income taxes for the periods presented:



	Year Ended December 31,
	2014			2013			2012
Current income taxes (benefit)
Federal	$	2,045		$	—		$	—
State	1,504			—			(26		)
	3,549			—			(26		)
Deferred income tax benefit
Federal	(130,693		)	(77,046		)	(60,676		)
State	(4,534		)	(650		)	(8,000		)
	(135,227		)	(77,696		)	(68,676		)
	$	(131,678	)	$	(77,696	)	$	(68,702	)

The following table reconciles the difference between the income tax benefit computed by applying the statutory tax rate to our loss before income taxes and our reported income tax benefit for the periods presented:



	Year Ended December 31,
	2014					2013					2012
Computed at federal statutory rate	$	(189,445	)	(35.0	)%	$	(77,268	)	(35.0	)%	$	(60,652	)	(35.0	)%
State income taxes, net of federal income tax benefit	(3,556		)	(0.6	)%	(650		)	(0.3	)%	(8,026		)	(4.6	)%
Change in valuation allowance	61,104			11.3	%	—			—	%	—			—	%
Other, net	219			—	%	222			0.1	%	(24		)	—	%
	$	(131,678	)	(24.3	)%	$	(77,696	)	(35.2	)%	$	(68,702	)	(39.6	)%

The following table summarizes the principal components of our deferred income tax liabilities and assets as of the dates presented:



	As of December 31,
	2014			2013
Deferred tax liabilities:
Property and equipment	$	6,347		$	248,164
Fair value of derivative instruments	57,707			—
Total deferred tax liabilities	64,054			248,164
Deferred tax assets:
Fair value of derivative instruments	—			1,665
Pension and postretirement benefits	2,370			2,248
Share-based compensation	7,171			6,907
Net operating loss (“NOL”) carryforwards	102,098			115,355
Deferred gains	33,704			—
Other	19,875			18,029
	165,218			144,204
Less: Valuation allowance	(105,615		)	(35,727		)
Total deferred tax assets	59,603			108,477
	$	4,451		$	139,687

As of December 31, 2014, we had federal NOL carryforwards of approximately $166.4 million, which, if not utilized, expire in 2032 and 2033, and state NOL carryforwards of approximately $67.5 million, which expire between 2024 and 2034.

As of December 31, 2013, we carried a valuation allowance against our state NOL carryforwards of $35.7 million. We incurred a pre-tax loss in 2014, primarily as a result of impairments to our oil and gas properties which, when aggregated with the prior two years, resulted in a pre-tax loss for the three year period ended December 31, 2014. We considered both the positive and negative evidence in determining whether it was more likely than not that some portion or all of our deferred tax assets will be realized. Primarily as a result of recent cumulative losses, we established a federal and state valuation allowance of $62.8 million against the deferred tax assets. The net effect of this and other adjustments resulted in an ending balance of $105.6 million for the deferred tax asset valuation allowance.

We had no liability for unrecognized tax benefits as of December 31, 2014 and 2013. There were no interest and penalty charges recognized during the years ended December 31, 2014, 2013 and 2012. Tax years from 2011 forward remain open for examination by the Internal Revenue Service and various state jurisdictions.