Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

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:

	2014			2013
Deferred tax assets:
Employee benefits	$	1,440		$	1,757
Inventories		6,966			5,923
Goodwill		874			1,358
Other		2,942			4,438
Foreign losses		4,300			—
Foreign tax assets valuation allowance		(4,300	)		—
Total deferred tax assets		12,222			13,476
Deferred tax liabilities:
Depreciation		81,628			54,973
Foreign earnings		—			1,816
Total deferred tax liabilities		81,628			56,789
Net deferred tax liabilities	$	69,406		$	43,313

Significant Components of Provision for Income Taxes

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

	2014		2013		2012
Current:
Federal	$	11,310	$	27,188	$	37,596
State		500		2,164		2,268
Foreign		1,084		842		1,581
Total current		12,894		30,194		41,445
Deferred		24,389		10,121		11,212
	$	37,283	$	40,315	$	52,657

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:

	2014						2013						2012
	Amount			Percent			Amount			Percent			Amount			Percent
U.S. statutory rate	$	32,505			35.0	%	$	43,820			35.0	%	$	55,507			35.0	%
State income taxes, net of federal tax benefit		1,882			2.0			2,097			1.7			2,199			1.4
Mining depletion		(3,035	)		(3.3	)		(2,751	)		(2.2	)		(2,606	)		(1.6	)
Foreign tax assets valuation allowance		4,300			4.6			—			—			—			—
Non-recognized benefit on foreign investments		2,980			3.2			—			—			—			—
Section 199 Manufacturing Benefit and other		(1,349	)		(1.4	)		(2,851	)		(2.3	)		(2,443	)		(1.6	)
	$	37,283			40.1	%	$	40,315			32.2	%	$	52,657			33.2	%