Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Significant Components of Deferred Tax Assets and Liabilities

Significant components of the Company’s deferred tax assets and liabilities as of December 31 are as follows:

	2017			2016
Deferred tax assets:
Employee benefits	$	836		$	1,349
Inventories		2,309			8,811
Natural gas derivatives		610			1,281
Goodwill & other intangibles		3,179			4,881
Net operating loss		59,536			51,722
Foreign tax credits		667			—
Other		2,029			2,028
Total deferred tax assets		69,166			70,072
Deferred tax liabilities:
Depreciation		14,332			71,308
Indefinite-lived intangibles		209			—
Foreign		26			—
Total deferred tax liabilities		14,567			71,308
Valuation Allowance		54,829			—
Net deferred tax liabilities	$	(230	)	$	(1,236	)

Significant Components of Provision for Income Taxes

Significant components of the provision for income taxes for the years ended December 31 are as follows:

	2017			2016			2015
Current:
Federal	$	(375	)	$	(495	)	$	1,509
State		(99	)		(496	)		120
Foreign		581			445			966
Total current		107			(546	)		2,595
Deferred		(2,134	)		(50,535	)		(56,800	)
	$	(2,027	)	$	(51,081	)	$	(54,205	)

Reconciliation of Income Taxes Computed at U.S. Statutory Tax Rate to Income Tax Expense

The reconciliation of income taxes computed at the U.S. statutory tax rate to the Company’s income tax expense for the years ended December 31 is as follows:

	2017						2016						2015
	Amount			Percent			Amount			Percent			Amount			Percent
U.S. statutory rate	$	(89,300	)		(35.0	)%	$	(45,923	)		(35.0	)%	$	(57,312	)		(35.0	)%
State income taxes, net of federal tax benefit		(5,684	)		(2.2	)		(3,283	)		(2.5	)		(3,474	)		(2.1	)
Mining depletion		(619	)		(0.2	)		(378	)		(0.3	)		(1,557	)		(0.9	)
Change in election for foreign tax credits		(667	)		(0.3	)		(2,753	)		(2.1	)		1,442			0.9
Foreign tax assets valuation allowance		—			—			—			—			1,230			0.7
Foreign investments		8,569			3.4			(323	)		(0.2	)		847			0.5
Stock compensation excess tax deficiency		876			0.3			789			0.6			—			—
Other permanent differences		1,806			0.7			790			0.6			4,619			2.8
Tax reform deferred rate change		28,163			11.0			—			—			—			—
Valuation allowance		54,829			21.5			—			—			—			—
	$	(2,027	)		(0.8	)%	$	(51,081	)		(38.9	)%	$	(54,205	)		(33.1	)%