Income Taxes

The components of income (loss) before income taxes are as follows:



	Year Ended December 31,
	2015		2014			2013
Domestic	$	880,044	$	1,102,101		$	944,378
Foreign	83,397		(18,183		)	(2,206		)
	$	963,441	$	1,083,918		$	942,172

The Company's provision for (benefit from) income taxes consists of the following:



	Year Ended December 31,
	2015		2014			2013
Current
Federal	$	225,617	$	300,610		$	215,903
State	23,966		37,351			22,249
Foreign	9,029		1,974			(137		)
	258,612		339,935			238,015
Deferred
Federal	29,820		40,950			94,471
State	2,807		22,714			(556		)
Foreign	7,157		(4,697		)	(183		)
	39,784		58,967			93,732
Total provision	$	298,396	$	398,902		$	331,747

A reconciliation of taxes computed at the statutory rate to the Company's income tax expense is as follows:



	Year Ended December 31,
	2015			2014			2013
Provision for federal income tax, at statutory rate	$	337,204		$	379,371		$	329,760
State income tax provision, net of federal income tax effect	17,403			40,012			14,364
Foreign income tax rate differential	(13,002		)	3,640			519
Manufacturing deduction	(24,185		)	(24,465		)	(16,275		)
Contingent tax liability	—			(1,626		)	(404		)
Noncontrolling interests	(6,662		)	(2,255		)	—
Other, net	(12,362		)	4,225			3,783
	$	298,396		$	398,902		$	331,747

The tax effects of the principal temporary differences between financial reporting and income tax reporting at December 31 are as follows:



	2015			2014
Net operating loss carryforward	$	17,679		$	18,200
Credit carryforward	746			694
Accruals	62,204			62,845
Allowance for doubtful accounts	4,617			1,998
Inventories	8,663			11,437
Other	7,747			7,660
Deferred taxes assets—total	101,656			102,834
Property, plant and equipment	(423,381		)	(398,683		)
Turnaround costs	(1,467		)	(2,289		)
Basis difference—consolidated partnerships	(200,627		)	(194,480		)
Deferred tax liabilities—total	(625,475		)	(595,452		)
Valuation allowance	(16,345		)	(11,011		)
Total net deferred tax liabilities	$	(540,164	)	$	(503,629	)

Balance sheet classifications
Current deferred tax asset	$	35,439		$	32,437
Noncurrent deferred tax liability	(575,603		)	(536,066		)
Total net deferred tax liabilities	$	(540,164	)	$	(503,629	)

At December 31, 2015, the Company had foreign and state net operating loss carryforwards of approximately $267,192, which will expire in varying amounts between 2016 and 2035 and are subject to certain limitations on an annual basis. Management believes the Company will realize the benefit of a portion of the net operating loss carryforwards before they expire, but to the extent that the full benefit may not be realized, a net operating loss valuation allowance has been recorded. The valuation allowance increased by $5,334 in 2015 due to the creation of additional state and foreign net operating loss carryforwards.

We do not consider the undistributed earnings of our foreign subsidiaries as of December 31, 2015 and 2014 to be permanently reinvested and, accordingly, all required income tax consequences have been considered on such income in accordance with current applicable rules.

The gross unrecognized tax benefits at December 31 are as follows:



	2015		2014
Beginning balance	$	—	$	2,501
Reductions due to statutes of limitations expiring	—		(2,501		)
Ending balance	$	—	$	—

There were no unrecognized tax benefits as of December 31, 2015 and 2014. The Company recognized gross unrecognized tax benefits of $2,501 during the year ended December 31, 2014. The effective income tax rate impact in 2014 was immaterial. The Company recognizes penalties and interest accrued related to unrecognized tax benefits in income tax expense.

The Company files income tax returns in the U.S. federal jurisdiction, various states and foreign jurisdictions. The Company is no longer subject to examinations by tax authorities before the year 2010.