Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Schedule of Components of Income Tax Expense (Benefit)

The provision for income taxes consisted of the following:



	For the years ended
(dollars in thousands)	December 31, 2016			December 31, 2015			December 31, 2014
Current tax provision:
Federal	$	57,605		$	60,826		$	39,576
State	6,933			7,164			8,947
Foreign	41			11			—
Total current provision	64,579			68,001			48,523

Deferred tax provision:
Federal	9,391			(9,855		)	16,037
State	2,644			(2,216		)	(1,202		)
Foreign	(47		)	—			—
Total deferred (benefit) provision	11,988			(12,071		)	14,835
Total provision	$	76,567		$	55,930		$	63,358

Schedule of Income (Loss) before Income Tax, Domestic and Foreign

Components of income (loss) before income taxes are as follows:



	For the years ended
	December 31, 2016			December 31, 2015			December 31, 2014

United States	$	211,419		$	147,427		$	165,289
Foreign	(4,611		)	(2,109		)	—
Total income before income taxes	$	206,808		$	145,318		$	165,289

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the federal statutory rate to our effective rate is as follows:



	For the years ended
	December 31, 2016		December 31, 2015		December 31, 2014

Federal statutory income tax rate	35.0	%	35.0	%	35.0	%
State income taxes, net of federal income tax benefit	3.3		2.5		2.1
Non-deductible expenses	0.7		2.0		0.3
Domestic manufacturing deduction	(1.4	)	(1.3	)	—
Unrecognized tax benefits	0.5		0.8		1.3
Valuation allowance	0.5		0.5		—
Other	(1.6	)	(1.0	)	(0.4	)
Total	37.0	%	38.5	%	38.3	%

Summary of Unrecognized Tax Benefits

The following is a reconciliation of the beginning and ending amount of unrecognized tax benefits (which excludes federal benefits of state taxes, interest, and penalties):



(dollars in thousands)
Balance at December 31, 2013	4,883
Increases in uncertain tax benefits as a result of tax positions taken in a prior year	206
Increases in uncertain tax benefits as a result of tax positions taken in the current year	2,429
Balance at December 31, 2014	7,518
Increases in uncertain tax benefits as a result of tax positions taken in the current year	1,845
Decreases in uncertain tax benefits from a lapse of applicable statute of limitations	(156		)
Balance at December 31, 2015	$	9,207
Increases in uncertain tax benefits as a result of tax positions taken in a prior year	287
Increases in uncertain tax benefits as a result of tax positions taken in the current year	1,367
Decreases in uncertain tax benefits from a lapse of applicable statute of limitations	(233		)
Decreases in uncertain tax benefits as a result of tax positions taken in a prior year	(2,028		)
Balance at December 31, 2016	$	8,600

Schedule of Deferred Tax Assets and Liabilities

Components of deferred tax assets and liabilities were as follows:



(dollars in thousands)	December 31, 2016			December 31, 2015
Deferred tax assets:
Inventories	$	1,440		$	1,228
Accrued liabilities	413			12,491
Stock-based compensation	2,544			1,378
Long-term incentive plan	1,600			834
State net operating loss carryforwards	1,509			2,152
Foreign net operating loss carryforwards	1,380			254
State tax credits	1,447			1,826
Federal benefit related to uncertain tax positions	2,724			2,697
Other	1,057			755
Deferred tax assets, gross	14,114			23,615
Valuation allowance	(1,772		)	(782		)
Total deferred tax assets, net	12,342			22,833

Deferred tax liabilities:
Property, plant, and equipment	(22,173		)	(20,441		)
Other	(1,518		)	(1,753		)
Total deferred tax liabilities	(23,691		)	(22,194		)

Net deferred tax (liabilities) assets	$	(11,349	)	$	639