(4)	INCOME TAXES

Our income tax expense was $396.5 million for the year ended December 31, 2014 compared to $33.9 million in 2013 and $12.1 million in 2012. Reconciliation between the statutory federal income tax rate and our effective income tax rate is as follows:


	Year Ended December 31,
	2014		2013			2012
Federal statutory tax rate	35.0	%		35.0	%		35.0	%
State	3.1			(2.3	)		0.7
State apportionment rate change	(0.2	)		(14.9	)		¾
Non-deductible executive compensation	0.2			0.7			1.4
Valuation allowances	0.2			3.5			8.8
Other	0.2			0.6			2.2
Consolidated effective tax rate	38.5	%		22.6	%		48.1	%

Income tax expense (benefit) attributable to income before income taxes consists of the following (in thousands):

		2014						2013									2012
		Current	Deferred		Total		Current			Deferred			Total			Current			Deferred		Total
U.S. federal	$	¾	$	361,152	$	361,152	$	¾		$	58,527		$	58,527		$	—		$	11,873	$	11,873
U.S. state and local		1		35,350		35,351		(143	)		(24,527	)		(24,670	)		(1,778	)		1,959		181
Total	$	1	$	396,502	$	396,503	$	(143	)	$	34,000		$	33,857		$	(1,778	)	$	13,832	$	12,054

Significant components of deferred tax assets and liabilities are as follows:

	December 31,
	2014			2013
	(in thousands)
Deferred tax assets:
Current
Deferred compensation	$	9,286		$	9,128
Current portion of asset retirement obligation		5,745			1,854
Cumulative mark-to-market loss		584			15,193
Net operating loss carryforward		—			23,079
Other		9,921			7,936
Total current		25,536			57,190
Non-current
Net operating loss carryforward		176,812			57,266
Deferred compensation		64,656			91,094
Equity compensation		25,833			22,800
AMT credits and other credits		4,447			4,122
Non-current portion of asset retirement obligation		104,063			86,126
Cumulative mark-to-market loss		65			¾
Other		987			1,116
Valuation allowance		(16,599	)		(14,781	)
Total non-current		360,264			247,743
Deferred tax liabilities:
Current
Net gain in AOCI related to hedge derivatives		—			(3,987	)
Other		(2,350	)		(1,789	)
Cumulative mark-to-market gain		(138,773	)		¾
Total current		(141,123	)		(5,776	)
Non-current
Depreciation, depletion and investments		(1,342,039	)		(1,010,757	)
Cumulative mark-to-market gain		(15,410	)		(6,424	)
Other		(310	)		(2,542	)
Total non-current		(1,357,759	)		(1,019,723	)
Net deferred tax liability	$	(1,113,082	)	$	(720,566	)

At December 31, 2014, deferred tax liabilities exceeded deferred tax assets by $1.1 billion. As of December 31, 2014, we have a $7.8 million valuation allowance on the deferred tax asset related to our deferred compensation plan for planned future distributions to certain executives to the extent that their estimated future compensation plus distribution amounts would exceed the $1.0 million deductible limit provided under I.R.C. Section 162(m). We also have an $8.8 million valuation allowance on our Oklahoma net operating loss carryforwards.

At December 31, 2014, we had regular net operating loss (“NOL”) carryforwards of $641.4 million and alternative minimum tax (“AMT”) NOL carryforwards of $557.3 million that expire between 2018 and 2034. Our federal deferred tax asset related to regular NOL carryforwards at December 31, 2014 was $130.8 million, which is net of the Accounting Standards Codification 718, “Stock Compensation” reduction for unrealized benefits, related to NOL’s created by excess tax deductions that have not generated current tax benefits. At December 31, 2014, we have AMT credit carryforwards of $665,000 that are not subject to limitation or expiration.

We file consolidated tax returns in the United States federal jurisdiction. We file separate company state income tax returns in Louisiana, Mississippi, Pennsylvania and Virginia and file consolidated or unitary state income tax returns in Oklahoma, Texas and West Virginia. We are subject to U.S. Federal income tax examinations for the years 2011 and after and we are subject to various state tax examinations for years 2010 and after. We have not extended the statute of limitation period in any income tax jurisdiction. Our policy is to recognize interest related to income tax expense in interest expense and penalties in general and administrative expense. We do not have any accrued interest or penalties related to tax amounts as of December 31, 2014. Throughout 2014, our unrecognized tax benefits were not material.