Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of the Income Tax Provision Allocated to Continuing Operations

Income tax expense consists of the following for the years ended December 31:

(Dollars in thousands)	2017		2016			2015
Current	$	16,657	$	(6,178	)	$	128
Deferred		14,325		2,143			1,097
Net operating loss carryforwards		1,039		(290	)		(6,793	)
Income tax provision (benefit)	$	32,021	$	(4,325	)	$	(5,568	)

Schedule of Effective Income Tax Rate Reconciliation

Income tax expense differs from the amount computed by applying the statutory federal income tax rate of 35% to income before income taxes due to the following for the years ended December 31:

(Dollars in thousands)	2017			2016			2015
U.S. federal statutory income tax	$	41,466		$	2,314		$	9,151
REIT income not subject to federal income tax		(20,651	)		(7,199	)		(14,110	)
U.S. tax rate change on deferred tax assets and liabilities		10,528			—			—
Intercompany profit-in-inventory elimination adjustment		—			1,465			—
Change in valuation allowance		140			162			488
State income taxes, net of federal income tax		2,608			(740	)		(838	)
Domestic production activities deduction		(1,511	)		(2	)		—
Permanent book-tax differences		(252	)		(218	)		(70	)
Research and development credits		(294	)		(689	)		—
All other items		(13	)		582			(189	)
Income tax provision (benefit)	$	32,021		$	(4,325	)	$	(5,568	)
Effective tax rate		27.0	%		(65.4	%)		(21.3	%)

Schedule of Deferred Tax Assets and Liabilities

The tax effects of significant temporary differences creating deferred tax assets and liabilities at December 31 were:

(Dollars in thousands)	2017			2016
Deferred tax assets:
Pensions	$	19,439		$	37,423
Other postretirement employee benefits		7,891			13,002
Net operating loss carryforwards		54			983
Inventories		353			443
Tax credits		2,443			2,207
Nondeductible accruals		2,566			2,067
Incentive compensation		1,131			1,643
Employee benefits		1,037			1,444
Other		88			120
Total deferred tax assets		35,002			59,332
Valuation allowance		(790	)		(650	)
Deferred tax assets, net of valuation allowance		34,212			58,682
Deferred tax liabilities:
Timber and timberlands, net		(1,432	)		(2,165	)
Property, plant and equipment, net		(12,683	)		(14,018	)
Other		(301	)		(448	)
Total deferred tax liabilities		(14,416	)		(16,631	)
Deferred tax assets, net	$	19,796		$	42,051

Summary of Tax Years Subject to Examination by Major Taxing Jurisdictions

The following table summarizes the tax years subject to examination by major taxing jurisdictions:

Jurisdiction		Years
Federal		2013 — 2017
Arkansas		2014 — 2017
Michigan		2013 — 2017
Minnesota		2013 — 2017
Idaho		2014 — 2017

Summary of Reconciliation of Unrecognized Tax Benefits

A reconciliation of the beginning and ending unrecognized tax benefits is as follows:

(Dollars in thousands)	2017			2016
Balance at January 1	$	850		$	—
Additions for tax positions of prior years		8			850
Reduction for tax positions of prior years		(294	)		—
Balance at December 31	$	564		$	850