Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Taxes

Schedule of current and deferred federal and state income tax expense (benefit)

The current and deferred federal and state income tax expense (benefit) for the years ended December 31 is as follows (in thousands):

	2015			2014			2013
Current income tax expense	$	6,391		$	94,312		$	72,599
Deferred income tax expense (benefit)		(103,338	)		(21,159	)		26,715
Total income tax expense (benefit)	$	(96,947	)	$	73,153		$	99,314

Schedule of reconciliation of statutory tax rates to actual effective tax rates

	2015			2014			2013
Statutory federal tax rate		35.0	%		35.0	%		35.0	%
State income taxes, net of federal benefit		6.3			4.6			3.8
Domestic manufacturing deduction		—			(4.8	)		(2.0	)
Noncontrolling interests		(2.1	)		13.9			3.4
Federal research and development tax credits		—			(1.5	)		(2.5	)
Other permanent differences		0.8			(2.8	)		0.1
Effective tax rate		40.0	%		44.4	%		37.8	%

Schedule of components of deferred tax assets and liabilities

        Significant components of the company's deferred tax assets and liabilities at December 31 are as follows (in thousands):

	2015			2014
Deferred tax assets
Accrued expenses and allowances	$	21,205		$	22,780
Inventories		21,559			20,546
Net operating loss carryforwards		61,148			33,347
Intangible Assets		28,553			—
Other		8,684			5,571
Subtotal		141,149			82,244
Less: valuation allowance		(26,835	)		(21,586	)
Total net deferred tax assets		114,314			60,658
Deferred tax liabilities
Property, plant and equipment		(511,596	)		(449,939	)
Intangible assets		—			(108,840	)
Other		(3,488	)		(8,361	)
Total deferred tax liabilities		(515,084	)		(567,140	)
Net deferred tax liability	$	(400,770	)	$	(506,482	)

Schedule of reconciliation of beginning and ending amount of unrecognized tax benefits

        A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):

	2015			2014			2013
Balance at January 1	$	17,338		$	26,564		$	22,245
Increases related to current year tax positions		—			1,050			1,050
Increases related to prior year tax positions		81			653			3,760
Decreases related to prior year tax positions		(719	)		(2,298	)		(491	)
Settlements with taxing authorities		(70	)		(8,631	)		—
Lapses in statute of limitations		(639	)		—			—
Balance at December 31	$	15,991		$	17,338		$	26,564