Deltic Timber (DEL) 10-K 3 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 13, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	DEL
Entity Registrant Name	DELTIC TIMBER CORP
Entity Central Index Key	1022469
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		12,582,089
Entity Public Float			$341,076,882

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets
Cash and cash equivalents	$2,761	$4,374
Trade accounts receivable - net	9,087	7,331
Inventories	11,494	12,439
Prepaid expenses and other current assets	5,964	3,155
Total current assets	29,306	27,299
Investment in real estate held for development and sale	56,139	57,953
Timber and timberlands - net	364,410	248,833
Property, plant, and equipment - net	74,164	75,259
Deferred charges and other assets	3,250	2,000
Total assets	527,269	411,344
Current liabilities
Trade accounts payable	6,814	8,198
Accrued taxes other than income taxes	2,149	2,210
Income taxes payable	0	1,077
Deferred revenues and other accrued liabilities	7,223	10,330
Total current liabilities	16,186	21,815
Long-term debt	203,000	90,000
Deferred tax liabilities - net	1,102	7,514
Other noncurrent liabilities	39,340	25,743
Commitments and contingencies
Stockholders' equity
Cumulative preferred stock - $.01 par, authorized 20,000,000 shares, none issued
Common stock - $.01 par, authorized 50,000,000 shares, 12,813,879 shares issued	128	128
Capital in excess of par value	86,575	84,796
Retained earnings	204,327	189,720
Treasury stock	-11,978	-5,693
Accumulated other comprehensive loss	-11,411	-2,679
Total stockholders' equity	267,641	266,272
Total liabilities and stockholders' equity	$527,269	$411,344

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Cumulative preferred stock, par value	$0.01	$0.01	$0.01
Cumulative preferred stock, shares authorized	20,000,000	20,000,000	20,000,000
Cumulative preferred stock, shares issued	0	0	0
Common stock, par value	$0.01	$0.01	$0.01
Common stock, shares authorized	50,000,000	50,000,000	50,000,000
Common stock, shares issued	12,813,879	12,813,879	12,813,879

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Net sales	$227,355	$199,702	$140,908
Costs and expenses
Cost of sales	156,135	130,752	94,706
Depreciation, amortization, and cost of fee timber harvested	18,342	15,131	10,642
General and administrative expenses	18,482	19,037	18,428
Total costs and expenses	192,959	164,920	123,776
Gain on involuntary conversion	0	881	0
Operating income	34,396	35,663	17,132
Equity in earnings of Del-Tin Fiber	0	1,084	959
Interest income	5	13	17
Interest and other debt expense, net of capitalized interest	-5,430	-4,578	-4,092
Gain on bargain purchase	0	3,413	0
Other income	284	3,229	20
Income before income taxes	29,255	38,824	14,036
Income taxes	-9,593	-12,632	-4,801
Net income	$19,662	$26,192	$9,235
Earnings per common share
Basic	$1.56	$2.06	$0.73
Assuming dilution	$1.55	$2.05	$0.73
Dividends declared per common share	$0.40	$0.40	$0.30
Weighted average common shares outstanding (thousands of shares)
Basic	12,497	12,566	12,525
Assuming dilution	12,553	12,624	12,588

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$19,662	$26,192	$9,235
Items related to employee benefit plans:
Net gain/(loss) arising during period (net of tax)	-8,895	10,973	-5,131
Reclassification adjustment for gains/(losses) included in net income (net of tax):
Amortization of prior service credit	6	4	4
Amortization of actuarial losses	278	568	874
Amortization of plan amendment	-121	-121	-121
Net change in other comprehensive income/(loss)	-8,732	11,424	-4,374
Comprehensive income	$10,930	$37,616	$4,861

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities
Net income	$19,662	$26,192	$9,235
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, amortization, and cost of fee timber harvested	18,342	15,131	10,642
Stock-based compensation expense	3,238	2,797	2,298
Deferred income taxes	-1,253	241	-649
Real estate development expenditures	-3,625	-3,982	-2,822
Real estate costs recovered upon sale	4,972	2,711	2,342
Timberland costs recovered upon sale	174	827	832
Equity in earnings of Del-Tin Fiber	0	-1,084	-959
Gain on previously held equity interest	0	-3,165	0
Gain on bargain purchase	0	-3,413	0
Net increase in liabilities for pension and other postretirement benefits	1,251	1,931	1,990
Decrease/(increase) in operating working capital other than cash and cash equivalents	-9,174	5,883	2,455
Other changes in assets and liabilities	-2,060	-1,927	-1,282
Net cash provided by operating activities	31,527	42,142	24,082
Investing activities
Capital expenditures requiring cash, excluding real estate development	-15,969	-19,396	-6,607
Timberland acquisition expenditures requiring cash	-118,203	-8,919	-14,527
Business acquisition, net of cash acquired	0	-5,170	0
Net change in purchased stumpage inventory	768	-1,486	1,159
Advances to Del-Tin Fiber	0	-1,025	-2,190
Repayments from Del-Tin Fiber	0	781	3,970
Net change in funds held by trustee	0	7	560
Other - net	1,105	1,416	800
Net cash required by investing activities	-132,299	-33,792	-16,835
Financing activities
Proceeds from borrowings	120,000	12,000	18,000
Repayments of notes payable and long-term debt	-7,000	-14,000	-20,111
Treasury stock purchases	-7,866	-2,224	-19
Common stock dividends paid	-5,055	-5,080	-3,797
Proceeds from stock option exercises	253	760	1,157
Excess tax benefits from stock-based compensation expense	160	408	590
Other - net	-606	-688	-745
Deferred financing costs	-727	-765	0
Net cash provided/(required) by financing activities	99,159	-9,589	-4,925
Net increase/(decrease) in cash and cash equivalents	-1,613	-1,239	2,322
Cash and cash equivalents at January 1	4,374	5,613	3,291
Cash and cash equivalents at December 31	$2,761	$4,374	$5,613

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Preferred stock [Member]	Common stock [Member]	Capital in excess of par value [Member]	Retained earnings [Member]	Treasury Stock [Member]	Accumulated other comprehensive loss [Member]
In Thousands, except Per Share data
Balance at beginning of year at Dec. 31, 2011			$128	$80,842	$163,170	($7,288)	($9,729)
Exercise of stock options				181
Shares purchased -131,947; 36,314; and 267 shares, respectively						-19
Net income	9,235				9,235
Net change in other comprehensive income/(loss), net of income taxes							-4,374
Stock-based compensation expense				2,298
Common stock dividends declared					-3,797
Restricted stock awards	-1,393			-1,393
Tax effect on stock awards				607
Forfeited restricted stock -none; 570; and 905 shares, respectively				62		-62
Shares issued for incentive plans -34,766; 44,249; and 67,494 shares, respectively						2,369
Dividends declared per common share	$0.30
Balance at end of year at Dec. 31, 2012	232,230	0	128	82,597	168,608	-5,000	-14,103
Exercise of stock options				123
Shares purchased -131,947; 36,314; and 267 shares, respectively						-2,224
Net income	26,192				26,192
Net change in other comprehensive income/(loss), net of income taxes							11,424
Stock-based compensation expense				2,797
Common stock dividends declared					-5,080
Restricted stock awards	-935			-935
Tax effect on stock awards				173
Forfeited restricted stock -none; 570; and 905 shares, respectively				41		-41
Shares issued for incentive plans -34,766; 44,249; and 67,494 shares, respectively						1,572
Dividends declared per common share	$0.40
Balance at end of year at Dec. 31, 2013	266,272	0	128	84,796	189,720	-5,693	-2,679
Exercise of stock options				-37
Shares purchased -131,947; 36,314; and 267 shares, respectively						-7,866
Net income	19,662				19,662
Net change in other comprehensive income/(loss), net of income taxes							-8,732
Stock-based compensation expense				3,238
Common stock dividends declared					-5,055
Restricted stock awards	-1,290			-1,290
Tax effect on stock awards				-132
Shares issued for incentive plans -34,766; 44,249; and 67,494 shares, respectively						1,581
Dividends declared per common share	$0.40
Balance at end of year at Dec. 31, 2014	$267,641	$0	$128	$86,575	$204,327	($11,978)	($11,411)

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Cumulative preferred stock, par value	$0.01	$0.01	$0.01
Cumulative preferred stock, shares authorized	20,000,000	20,000,000	20,000,000
Cumulative preferred stock, shares issued	0	0	0
Common stock, par value	$0.01	$0.01	$0.01
Common stock, shares authorized	50,000,000	50,000,000	50,000,000
Common stock, shares issued	12,813,879	12,813,879	12,813,879
Treasury stock shares, balance at beginning of year	134,609	141,974	208,296
Treasury stock, shares purchased	131,947	36,314	267
Forfeited restricted stock	0	570	905
Treasury stock, shares issued for incentive plans	34,766	44,249	67,494
Treasury stock shares, balance at end of year	231,790	134,609	141,974

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Significant Accounting Policies	Note 1 – Significant Accounting Policies
	Description of Business — Deltic Timber Corporation (“Deltic” or the “Company”) is a natural resources company engaged primarily in the growing and harvesting of timber and the manufacturing and marketing of lumber and medium density fiberboard (“MDF”). Deltic owns approximately 530,000 acres of timberland, primarily in Arkansas and north Louisiana. The Company’s sawmill operations are located at Ola in central Arkansas and at Waldo in south Arkansas, and the MDF plant is located near El Dorado, Arkansas. In addition to its timber, lumber, and MDF operations, the Company is engaged in real estate development in central Arkansas.
	Business Environment — The Company is primarily a wood products producer operating in a commodity-based business environment with a major diversification in real estate development. This environment is affected by a number of factors including general economic conditions, interest rates, credit availability, building product imports, foreign exchange rates, housing starts, new and existing housing inventory, foreclosures, residential repair and remodeling, commercial construction and repair, industry capacity and production levels, the availability of contractors for logging, hauling, and shipping, the availability of raw materials, natural gas pricing, costs of fuel, and weather conditions.
	Principles of Consolidation — The consolidated financial statements of Deltic Timber Corporation include the accounts of Deltic, all majority-owned subsidiaries, and any variable interest entities of which it is the primary beneficiary. Equity investments and joint ventures are accounted for under the equity method, if it is determined that the Company does not have control of the entity. Significant intercompany transactions and accounts have been eliminated.
	Business Combinations — The Company accounts for business combinations using the acquisition method. The assets acquired and liabilities assumed are measured at fair value on the acquisition date using appropriate valuation methods. The operations of the acquisitions are included in the consolidated financial statements from the date of acquisition. (For additional information, see Note 4 – Business Combinations.)
	Use of Estimates — In the preparation of the Company’s financial statements in conformity with accounting principles generally accepted in the United States of America, management has made a number of estimates and assumptions related to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities. Actual results may differ from those estimates.
	Cash Equivalents — Cash equivalents include investments that have a maturity of three months or less from the date of purchase.
	Accounts Receivable and Allowance for Doubtful Accounts — The Company records trade accounts receivable at net realizable value. This value includes an appropriate allowance for estimated uncollectible accounts to reflect any loss anticipated on the trade accounts receivable balances and is charged to the provision for doubtful accounts. The allowance is based upon review of specific receivables outstanding and considers factors such as current overall economic conditions, industry-specific economic conditions, historical customer performance, and anticipated customer performance. In the consolidated statements of income, bad debt expense is included in cost of sales. Provisions for bad debt expense were $150,000, $158,000, and $133,000 in 2014, 2013, and 2012, respectively. Charges to the allowance for write-downs were $188,000, $137,000, and $72,000 in 2014, 2013, and 2012, respectively. At December 31, 2014 and 2013, the balance in the allowance account was $123,000 and $172,000, respectively.
	Inventories — Inventories of logs, wood fiber, lumber, MDF, and supplies are stated at the lower of cost or market within Deltic’s operating areas, primarily using the average cost method. Log costs include harvest and transportation costs as appropriate. Lumber and MDF costs include materials, labor, and production overhead. (For additional information, see Note 2 – Inventories.)
	Investment in Del-Tin Fiber — On April 1, 2013, the Company acquired the remaining 50 percent membership interest of Del-Tin Fiber, which had been accounted for as an equity method investment and is now included as a wholly-owned consolidated subsidiary. (For additional information, see Note 4 – Business Combinations.)
	Investment in Real Estate Held for Development and Sale — Real estate held for development and sale includes direct costs of land and land development and indirect costs, including amenities. Indirect and amenity costs are allocated to individual lots or acreage sold based on relative retail sales values. Direct costs are allocated to a specific neighborhood or commercial real estate tract, while indirect costs for the Company’s four developments – Chenal Valley, Wildwood Place, Chenal Downs, and Red Oak Ridge – are allocated to neighborhoods over the entire respective development area based on relative retail sales values.
	Timber and Timberlands — Timber and timberlands, which include timberland, fee timber, purchased stumpage inventory, and logging facilities, are stated at cost, less the cost of fee timber harvested and accumulated depreciation of logging facilities, and include no estimated future reforestation costs. The cost of timber consists of fee timber acquired and reforestation costs, which include site preparation, seedlings, and labor. The cost of fee timber harvested is based on the volume of timber harvested in relation to the estimated volume of timber recoverable. Logging facilities, which consist primarily of roads constructed and other land improvements, are depreciated using the straight-line method over a ten-year estimated life. The Company estimates its fee timber inventory using statistical information and data obtained from physical measurements and other information gathering techniques. Fee timber carrying costs, commercial thinning, silviculture, and timberland management costs are expensed as incurred.
	The Company classifies its timberlands and fee timber as either strategic or non-strategic. Strategic timberlands, including pine forest and pine plantations, are prime pine sawtimber-growing platforms located within or immediately adjacent to the Company sawmills’ operating regions. Deltic manages these acres using modern silviculture methods to achieve optimal volume and quality of its pine sawtimber. The Company harvests pine sawtimber and pine pulpwood in accordance with its harvest plans and generally converts pine sawtimber into lumber in its own sawmills and sells pine pulpwood, hardwood pulpwood, and hardwood sawtimber in the market. Upon harvest, strategic timberlands are reforested. The Company’s timberland acquisition program is focused on the acquisition of pine-growing timberland in its current operating regions. This investment in strategic fee timber is a “productive asset,” and any occasional sale of strategic timberland or any expenditure to acquire such timber and timberlands is included in and classified as an investing activity in the Company’s consolidated statements of cash flows. The Company has legacy hardwood and other acreage which cannot be harvested for conversion in Company sawmills, reforested as pine plantations, or managed efficiently using modern silviculture methods either due to the size of the tract or lack of proximity to other Deltic fee timberlands. These timberlands have been identified as non-strategic and/or higher and better use timberlands and are expected to be sold over time. The Company considers these sales to be an operating activity of its Woodlands segment.
	In order to acquire and sell assets, primarily timberlands, in a tax efficient manner, the Company enters into tax-deferred, like-kind exchange (“LKE”) transactions when possible. The Company generally enters into forward transactions, in which property is sold and the proceeds are reinvested by acquiring similar property, and reverse transactions, in which property is acquired and similar property is subsequently sold. A qualified LKE intermediary is used to facilitate LKE transactions. Proceeds from forward LKE transactions are held by the intermediary and are classified as restricted cash, because the funds must be reinvested in similar properties. If the acquisition of suitable LKE properties is not completed within 180 days of the sale of the Company-owned property, the proceeds are distributed to Deltic by the intermediary and are reclassified as available cash, and applicable income taxes are determined. Amounts deposited with a third party towards the potential future purchase of property are included in deferred charges and other assets in the consolidated balance sheets and as an investing activity as changes in funds held by trustee in the consolidated statements of cash flows. The Company had no proceeds from land sales deposited with an LKE intermediary at December 31, 2014 or 2013. An exchange accommodation titleholder, a type of variable interest entity, is used to facilitate reverse like-kind exchanges. The acquired assets are held by the exchange accommodation titleholder until the exchange transactions are complete. If the Company determines that it is the primary beneficiary of the exchange accommodation titleholder, Deltic includes the assets held by the exchange accommodation titleholder in timber and timberlands assets on the consolidated balance sheets and recognizes any income or expense attributed to the property in the consolidated income statements.
	Property, Plant, and Equipment — Property, plant, and equipment assets are stated at cost less accumulated depreciation. Depreciation of buildings, equipment, and other depreciable assets is calculated primarily using the straight-line method. Expenditures that substantially improve and/or increase the useful life of facilities or equipment are capitalized. Maintenance and repair costs are expensed as incurred. Gains and losses on disposals or retirements are recognized in the period they occur.
	Property, plant, and equipment assets are evaluated for possible impairment on a specific asset basis or in groups of similar assets, as applicable, whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future net cash flows to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment loss is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell, and depreciation ceases.
	Revenue Recognition — The Company recognizes revenue when the following criteria are met: (1) persuasive evidence of an agreement exists, (2) delivery has occurred or services have been rendered, (3) the price to the buyer is fixed and determinable, and (4) collectability is reasonably assured. Delivery is not considered to have occurred until the customer takes title and assumes the risks and rewards of ownership. Revenue from the sale of lumber, MDF, and wood by-products is recorded at the time of shipment due to terms of such sale being designated free on board (“f.o.b.”) shipping point. Revenue from consignment sales is recorded when the customer assumes ownership of the product. Revenue from the sale of timber-cutting rights to third parties is recorded when legal title passes to the purchaser, which is generally upon delivery of a legally executed timber deed and receipt of payment for the timber. Revenue from intersegment timber sales is recorded when the timber is harvested; such intersegment sales, which are made at prices which generally approximate market within Deltic’s operating area, are eliminated in the consolidated financial statements.
	Revenue from the leasing of land for hunting purposes is deferred when received and subsequently recognized over the one-year lease term, which begins September 1 of each year. At December 31, 2014 and 2013, the Company had deferred hunting lease revenue totaling $2,009,000 and $1,684,000, respectively, reflected in the consolidated balance sheets in deferred revenues and other accrued liabilities. Revenue from mineral lease rental payments is deferred when received and recognized ratably over the lease term. At December 31, 2014 and 2013, the Company had deferred mineral lease revenue of $1,140,000 and $2,085,000, respectively, of which $383,000 and $649,000 were included in other noncurrent liabilities for 2014 and 2013, respectively, and $757,000 and $1,436,000 were included in other current liabilities, respectively. Mineral royalty payments are recognized when received. Revenue from sales of timberland and real estate is recorded when the sale is closed and legal title is transferred and the buyer’s initial and continuing investment is adequate, which is generally at the time the purchaser executes the real estate closing documents and makes payment to the title company handling the closing.
	Income Taxes — The Company uses the asset and liability method of accounting for income taxes. Under this method, the provision for income taxes includes amounts currently payable and amounts deferred as tax assets and liabilities, based on differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities, and is measured using the enacted tax rates that are expected to be in effect when the differences reverse. Deferred tax assets are reduced by a valuation allowance, which is established when it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized. The effect on deferred tax assets and liabilities of a change in tax law is recognized in income in the period that includes the enactment date. The Company continuously reviews state and federal tax returns for uncertain tax provisions. Liabilities for uncertain tax positions are recorded if it is deemed more-likely-than-not that the positions will be sustained upon examination by the taxing authorities. These liabilities are adjusted in the period in which it is determined that the issue is settled with the relevant taxing authority, or there has been an expiration of statute of limitation for a tax year in question, or a change in tax laws, or other facts become known.
	Property Taxes — Property taxes applicable to the Company’s assets are estimated and accrued in the period of assessment. At December 31, 2014 and 2013, the Company had accrued property tax expense totaling $1,894,000 and $1,798,000, respectively, reflected in the consolidated balance sheets in accrued taxes other than income taxes.
	Share-Based Compensation — The Company applies a fair value-based measurement method in accounting for share-based payment transactions with employees, recognizing the cost as the services are performed. (For additional information, see Note 17 – Incentive Plans.)
	Pensions and Other Postretirement Benefits — The Company sponsors both qualified and nonqualified, noncontributory, defined benefit retirement plans that cover all eligible employees, excluding employees of the subsidiaries. Benefits are based on years of service and final career-average-pay formulas as defined by the plans. The qualified plan is funded to accumulate sufficient assets to provide for accrued benefits. The nonqualified plan, a supplemental executive plan, is not funded; payments to retirees due under this plan are made on a monthly basis.
	The Company also sponsors a defined benefit health care plan and a life insurance benefit plan for all eligible retired employees, excluding employees of the subsidiaries. The Company measures the costs of its obligations for these plans based on its health care cost trends and actuarial assumptions, including discount rates, mortality rates, assumed rates of return, compensation increases, and turnover rates. The Company reviews its assumptions on an annual basis and makes modifications to the assumptions based on current rates and trends when it is appropriate to do so. The effect of modifications to those assumptions is recorded in accumulated other comprehensive income/(loss) and amortized to net periodic cost over future periods using the corridor method. The Company believes that the assumptions utilized in recording its obligations under its plans are reasonable based on its experience and market conditions.
	Net periodic costs are recognized as employees render the services necessary to earn these post- retirement benefits. (For additional information, see Note 16 – Employee and Retiree Benefit Plans.)
	Advertising Costs — Advertising costs, primarily related to marketing efforts for the Company’s real estate developments, are expensed as incurred. These costs amounted to $764,000 in 2014, $716,000 in 2013, and $732,000 in 2012 and are reflected in the consolidated statements of income.
	Capitalized Interest — The Company capitalizes interest for qualifying assets during construction by applying the Company’s capitalization rate to the average amount of accumulated expenditures for the asset during the period. Interest is most often capitalized as an indirect cost for real estate development in the Company’s real estate operations. (For additional information, see Note 18 – Supplemental Cash Flows Disclosures.)
	Timberland Acquisition Expenditures — These expenditures are the costs incurred to purchase timber and timberland, and the costs which are allocated to timber, reforestation, or land are based on various factors such as age and number of trees on the acreage acquired. These expenditures are classified as investing activities in the Company’s consolidated statements of cash flows.
	Capital Expenditures — Capital expenditures include additions to investment in real estate held for development and sale; capitalized reforestation costs and logging facilities of timber and timberlands; and property, plant, and equipment.
	Net Change in Purchased Stumpage Inventory — Purchased stumpage inventory consists of timber-cutting rights purchased from third parties specifically for use in the Company’s sawmills. Depending on the timing of acquisition and usage of this acquired stumpage inventory, the net change in this inventory can either be a source or use of cash in the Company’s consolidated statements of cash flows.
	Earnings per Common Share — Basic earnings per share is computed using the two-class method and is based on earnings available to common shareholders less accrued preferred dividends, if any, and the weighted average number of common shares outstanding. The diluted earnings per share amounts are computed based on earnings available to common shareholders and the weighted average number of common shares outstanding, including shares assumed to be issued under the Company’s stock incentive plans using the treasury-stock method, unless anti-dilutive. (For a reconciliation of amounts used in per share computations, see Note 19 – Earnings per Share.)
	Shipping and Handling Costs — Shipping and handling costs, such as freight to the customers’ destinations, are included in cost of sales in the Company’s consolidated statements of income. These costs, when included in the amount invoiced to customers, are also recognized in net sales.
	Off-Balance Sheet Arrangements — The Company evaluates its transactions to determine if any variable interest entities exist. If it is determined that Deltic is the primary beneficiary of a variable interest entity, that entity is consolidated into Deltic’s financial statements.
	Effect of Recently Issued Authoritative Accounting Guidance — Financial Accounting Standards Update (“ASU”) No. 2014-09, “Revenue from Contracts with Customers,” requires an entity to recognize the amount of revenue it expects to be entitled to for the transfer of promised goods or services to customers. This ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for the Company on January 1, 2017, and early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company continues to evaluate the standard and has not yet selected a transition method but believes the standard will have little impact on its consolidated financial statements and disclosures.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventories	Note 2 – Inventories
	Inventories at December 31 consisted of the following:
	(Thousands of dollars)	2014		2013
	Raw materials   - Logs	$	772		1,612
	- Del-Tin – wood fiber		384		440
	Finished goods  - Lumber		4,168		4,145
	- Medium density fiberboard (“MDF”)		3,889		3,110
	- MDF consigned to others		926		708
	Supplies		1,355		2,424
		$	11,494		12,439
	The Company utilizes the lower of cost or market basis for determining inventory-carrying values. Lumber and MDF inventory amounts at December 31, 2014 and 2013 are stated at the lower of cost or net realizable value.

Prepaid_Expenses_and_Other_Cur

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Note 3 – Prepaid Expenses and Other Current Assets
	Prepaid expenses and other current assets at December 31 consisted of the following:
	(Thousands of dollars)	2014		2013
	Short-term deferred tax assets	$	2,087		1,901
	Refundable income taxes		2,537		109
	Prepaid expenses		654		692
	Other current assets		686		453
		$	5,964		3,155

Business_Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Business Combinations	Note 4 – Business Combinations
	On April 1, 2013, the Company acquired the remaining 50 percent membership interest of Del-Tin Fiber L.L.C. (“Del-Tin Fiber”) for an agreed-upon amount of approximately $20,000,000, which was considered to be comprised of a cash payment of $5,170,000 and the value of 50 percent of the long-term debt. Del-Tin Fiber operates an MDF manufacturing facility in El Dorado, Arkansas with a rated annual production capacity of 150,000,000 square feet, on a  3/4-inch basis. The acquisition resulted in Deltic obtaining a controlling financial interest in Del-Tin Fiber due to the Company’s 100 percent ownership of the membership interest of Del-Tin Fiber. As a result, Deltic began treating Del-Tin Fiber as a consolidated subsidiary of the Company as of the acquisition date. With this consolidation, on April 1, 2013, Deltic’s Consolidated Balance Sheets included the $29,000,000 of long-term debt of Del-Tin Fiber, which represents the L.L.C.’s recorded liability for the outstanding industrial bonds due 2027. This acquisition was consistent with Deltic’s strategy of growth through acquisitions and vertical integration, since Del-Tin Fiber uses residual by-products generated by Deltic’s sawmill operations as the raw material in its manufacturing process.
	Prior to this acquisition the Company owned 50 percent of the membership interest of Del-Tin Fiber and reported it as an equity method investment. In accordance with ASC 805, Deltic accounted for the acquisition as a business combination achieved in stages. Thus, the Company remeasured the carrying amount of its previously held investment in the joint venture to current fair value and recorded a $3,165,000 pretax remeasurement gain, determined by the amount by which the acquisition-date fair value of this investment, of $10,786,000, exceeded its previous carrying amount of $7,621,000. This gain was included in other income in the Company’s Consolidated Statements of Income for the year ended December 31, 2013.
	The acquisition date fair value of the Company’s existing 50 percent equity interest in Del-Tin Fiber was derived by applying the ownership percentage to the fair value of the net assets of Del-Tin Fiber. It was determined that no discounting was required, since prior to the acquisition, there was equally shared control of the joint venture by the owning members without specific benefit identified that related to the existence of control. In addition, Deltic continues to operate the existing facility to produce MDF.
	The fair value of assets acquired and liabilities assumed was determined using a combination of various methodologies, as appropriate, depending on the asset type and classification. Current assets and liabilities were valued at book value, since carrying value approximated fair value. Property, plant, and equipment assets were valued under various methodologies, including the market approach using comparable sales for real estate and the cost approach discounted for obsolescence for plant and equipment. Intangible assets were valued using the discounted income approach and using a discount rate of 15 percent. Long-term debt was valued at book value, since it approximated fair value. There was no tax-deductible goodwill as a result of the Del-Tin Fiber acquisition.
	The total cost of the acquisition has been allocated to the assets acquired and the liabilities assumed based upon their estimated fair values at the date of the acquisition and is presented in the next table.
	The purchase price allocated to the net tangible and intangible assets acquired and liabilities assumed based on their fair values as of the acquisition date and the calculation of the gain on bargain purchase were as follows:
	(Thousands of dollars)
	Accounts receivable		$	4,229
	Inventories			4,805
	Other current assets			360
	Property, plant, and equipment			40,960
	Intangible assets1			1,700
	Other assets			171
	Current liabilities			(1,653	)
	Deferred tax liabilities			(2,203	)
	Long-term liabilities			(29,000	)
	Net assets acquired			19,369
	Cash paid			(5,170	)
	Fair value of previously held investment in Del-Tin Fiber			(10,786	)
	Gain on bargain purchase		$	3,413
		1	The acquired intangible assets consist of internally developed software which is being amortized over three years.
	The purchase price allocation resulted in the recognition of a gain on bargain purchase of approximately $3,413,000, which was included in the Consolidated Statements of Income for the year ended December 31, 2013. The gain on bargain purchase was the result of the fair value of the identifiable net assets acquired exceeding the purchase price paid for the acquisition. The seller, Deltic’s former joint venture partner, was motivated to sell its half of Del-Tin Fiber in order to facilitate the sale of its remaining building products business to a major building products company that had no interest in owning a membership interest in a joint venture. This sale was part of the former joint venture partner’s stated plan to divest itself of its building product assets by the end of the year 2013.
	Transaction costs related to the acquisition of Del-Tin Fiber were insignificant and were expensed as incurred. The cash paid to the seller at the closing of the acquisition was funded by cash on hand.
	The results of Del-Tin Fiber’s operations have been included in the consolidated financial statements subsequent to the acquisition date and were included in the Company’s Manufacturing segment. Subsequent to the acquisition date, for the year ended December 31, 2013, the Company included net sales of approximately $47,812,000, from Del-Tin Fiber in its Consolidated Statements of Income. Deltic’s operating income for the year ended December 31, 2013, included $3,068,000 from Del-Tin Fiber operations.
	The following unaudited supplemental pro forma financial information for the years ended December 31, 2013 and 2012 represents the results of operations of Deltic Timber Corporation as if the Del-Tin Fiber acquisition had occurred on January 1, 2012. This information is based on historical results of operations, adjusted for certain acquisition accounting adjustments, and does not purport to represent Deltic’s actual results of operations as if the acquisition transaction described above would have occurred as of January 1, 2012, nor is it necessarily indicative of future results.
			Twelve Months Ended
			December 31,
	(Thousands of dollars, except per share amounts)		2013			2012
	Net sales		$	217,268		$	207,446
	Net income			21,193			8,846
	Basic earnings per common share			1.69			0.71
	Diluted earnings per common share			1.68			0.7

Timber_and_Timberlands

Timber and Timberlands	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Timber and Timberlands	Note 5 – Timber and Timberlands
	Timber and timberlands at December 31 consisted of the following:
	(Thousands of dollars)	2014			2013
	Purchased stumpage inventory	$	1,620			2,388
	Timberlands		155,704			102,609
	Fee timber		322,714			253,768
	Logging facilities		2,720			2,628
			482,758			361,393
	Less accumulated cost of fee timber harvested and facilities depreciation		(118,670	)		(113,056	)
	Strategic timber and timberlands		364,088			248,337
	Non-strategic timber and timberlands		322			496
		$	364,410			248,833
	In 1999, the Company initiated a program to identify and sell non-strategic timberlands and to use the sales proceeds to purchase pine timberlands that are strategic to its operations. As the Company identifies these acres and determines that they are either smaller tracts of pine timberland that cannot be strategically managed or are tracts of hardwood bottomland that cannot be converted into pine-growing acreage, they will be sold. As of December 31, 2014 and 2013, approximately 655 acres and 1,000 acres, respectively, were available for sale. Included in the Woodlands operating income are gains from sales of timberland of $857,000, $1,715,000, and $1,910,000 in 2014, 2013, and 2012, respectively. Occasionally Deltic engages in land-for-land exchanges that are recorded as sales due to the nature of the land involved. There were no non-monetary land exchanges in 2014, 2013, or 2012. Deltic acquired 72,170 acres of timberland for $118,203,000 in 2014 and 7,004 acres for $8,919,000 in 2013 in the Company’s current operating area. Deltic invests in and holds strategic fee timber as a productive asset, and any expenditure to acquire such timber and timberlands is an investing activity on the Company’s Consolidated Statements of Cash Flows.
	Cost of fee timber harvested amounted to $5,544,000, $4,494,000, and $4,497,000 in 2014, 2013, and 2012, respectively. Depreciation of logging facilities was $91,000, $92,000, and $94,000 for the years 2014, 2013, and 2012, respectively.

Property_Plant_and_Equipment

Property, Plant, and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	Note 6 – Property, Plant, and Equipment
	Property, plant, and equipment at December 31 consisted of the following:
	(Thousands of dollars)	Range of	2014			2013
		Useful Lives
	Land	N/A	$	947			947
	Land improvements	10-20 years		8,163			8,835
	Buildings and structures	10-20 years		22,680			22,599
	Machinery and equipment	3-15 years		152,641			145,741
				184,431			178,122
	Less accumulated depreciation			(110,267	)		(102,863	)
			$	74,164			75,259
	Depreciation of property, plant, and equipment charged to operations was $12,707,000, $10,544,000, and $6,051,000 in 2014, 2013, and 2012, respectively. Gains/(losses) on disposals or retirements of assets included in operating income were $(1,071,000), $362,000, and $(128,000) in 2014, 2013, and 2012, respectively.

Deferred_Revenues_and_Other_Ac

Deferred Revenues and Other Accrued Liabilities	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Deferred Revenues and Other Accrued Liabilities	Note 7 – Deferred Revenues and Other Accrued Liabilities
	Deferred revenues and other accrued liabilities at December 31 consisted of the following:
	(Thousands of dollars)	2014		2013
	Deferred revenues – current	$	3,310		3,697
	Vacation accrual		1,312		1,290
	Deferred compensation		1,166		3,442
	All other current liabilities		1,435		1,901
		$	7,223		10,330

Other_Noncurrent_Liabilities

Other Noncurrent Liabilities	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Other Noncurrent Liabilities	Note 8 – Other Noncurrent Liabilities
	Other noncurrent liabilities at December 31 consisted of the following:
	(Thousands of dollars)	2014		2013
	Accumulated postretirement benefit obligation	$	12,343		10,391
	Excess retirement plan		9,372		4,457
	Accrued pension liability		14,955		6,383
	Deferred revenue – long-term portion		383		649
	Uncertain tax positions liability		—		1,185
	All other noncurrent payables		2,287		2,678
		$	39,340		25,743

Credit_Facilities

Credit Facilities	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Credit Facilities	Note 9 – Credit Facilities
	The Company has an agreement with SunTrust Bank together with other banks, which provides an unsecured and committed revolving credit facility totaling $430,000,000 and includes an option to request an increase in the amount of aggregate revolving commitments by $50,000,000. The most recent amendment of this credit facility occurred on November 18, 2014, and expires on November 18, 2019. To facilitate the amendment, $700,000 in fees were incurred and are being amortized as additional interest over the term of the agreement together with the remaining unamortized prior costs of $967,000. At December 31, 2014 and 2013, $134,000,000 and $21,000,000, respectively, were outstanding and included in long-term debt. As of December 31, 2014 and 2013, $296,000,000 and $319,000,000, respectively, were available in excess of all borrowings outstanding under or supported by the respective facilities. Borrowings under the current agreement bear interest at a base rate or an adjusted Eurodollar rate plus an applicable margin, depending upon the type of loan the Company executes. The applicable margin component of the interest rate varies with the type of loan and the Company’s total debt to capital ratio. The agreement contains certain restrictive financial covenants, including a leverage ratio of no greater than .65 to 1, minimum timber market value greater than 175 percent of outstanding total senior indebtedness, and limitations on the incurrence of debt. Fees associated with the current revolving credit facility include a commitment fee of .20 to .35 percent per annum on the unused portion of the committed amount.
	The Company may also borrow up to $1,000,000 under a short-term credit facility with BancorpSouth. The agreement expires December 31, 2015, with annual renewal. The amount available to the Company under this facility is reduced by any borrowings by the Company. As of December 31, 2014 and 2013, Deltic had no borrowings outstanding under this line of credit, resulting in $1,000,000 available to the Company. Borrowings bear interest based upon the New York Prime rate. Deltic also has an agreement with BancorpSouth to provide letters of credit. New letters of credit are requested by the Company and are approved and issued by BancorpSouth on a case-by-case basis. Outstanding letters of credit as of December 31, 2014 and 2013 were $620,000 and $554,000, respectively.

Indebtedness

Indebtedness	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Indebtedness	Note 10 – Indebtedness
	The Company’s indebtedness at December 31 consisted of the following:
	(Thousands of dollars)		2014			2013
	Notes payable, 1.67%¹, due 2019 (See Note 9 – Credit Facilities)		$	134,000			21,000
	Senior notes payable, 6.10%, due 2016			40,000			40,000
	Union County, Arkansas Taxable Industrial Revenue Bonds, .29%², due 2027			29,000			29,000
	Long-term debt		$	203,000			90,000
		¹	Weighted average interest rate for Notes payable at December 31, 2014 and 2013 was 1.67% and 1.54%, respectively.
		²	Weighted average interest rate for Bonds at December 31, 2014 and 2013 was .29% and .31%, respectively.
	The Company has private placement debt outstanding of $40,000,000 of Series A Senior Notes (“Notes”) with Pacific Coast Farm Credit, a division of American AgCredit, due and payable December 18, 2016. The interest rate for the Notes has been 6.10 percent since December 18, 2008, and will remain at that rate for the remainder of the term of the Notes. No installment payments are required, but the terms allow for prepayments at the option of the Company. The agreement contains certain restrictive financial covenants, including a maximum funded debt to capitalization (“leverage”) ratio of .65 to 1, and a requirement to maintain a timber market value greater than 175 percent of outstanding total senior indebtedness. An amended agreement for the Notes was made effective December 1, 2014. The amended agreement made changes to certain financial covenants by changing the leverage ratio to be .65 to 1, and the fixed charge coverage ratio and consolidated net worth covenants were eliminated. All covenant requirements of the Notes are now the same as for the revolving credit facility.
	With consolidation of Del-Tin Fiber into the Company’s financial statements on April 1, 2013, Deltic’s long-term debt includes $29,000,000 in Union County, Arkansas Taxable Industrial Revenue Bonds (Del-Tin Fiber project) 1998 Series due October 1, 2027 (the “Bonds”). The Bonds were issued by Union County, Arkansas in the amount of $60,000,000 in December 1998 to finance completion of the construction of the MDF plant as well as the acquisition, construction, and improvement of certain sewage and solid waste disposal facilities related to the MDF plant. On September 1, 2004, $31,000,000 of the Bonds were retired. Neither the State of Arkansas, nor Union County, Arkansas has any liability under the Bonds. Del-Tin Fiber and Union County contemporaneously entered into a lease agreement (the “Lease Agreement”) that obligated Del-Tin Fiber to make lease payments in an amount necessary to fund the debt service on the Bonds. The Bonds were payable solely from the proceeds of the letters of credit issued to support the respective Bonds and from Company payments under the Loan Agreement and the Lease Agreement with Union County, Arkansas. The Company has unconditionally guaranteed the payment of all amounts owing under the Bonds to the bondholders. The Company’s indebtedness has been presented in these financial statements as though the Company was directly liable for the Bonds. If the Bonds are not remarketed as allowed under the agreement, the letter of credit and the commitment of the lenders are available to support repayment. Prior to the April 1, 2013 acquisition of Del-Tin Fiber, Deltic was a guarantor of one-half of the letter of credit supporting the Bonds. These Bonds bear interest at a variable rate determined weekly by the remarketing agent of the Bonds. Interest is due on the first business day of the month, and all unpaid interest and all principal is due on October 1, 2027. The average interest rate on the Bonds was .29 percent in 2014, .38 percent in 2013, and .70 percent in 2012.
	As of December 31, 2014, the scheduled maturities of long-term debt for the next five years are none in 2015, $40,000,000 in 2016, none in 2017 or 2018, and $134,000,000 in 2019. (For additional information regarding financial instruments, see Note 9 – Credit Facilities and Note 13 – Fair Value of Financial Instruments.)
	The table below sets forth the ratio requirements of the covenants in both the revolving credit facility and Senior Notes Payable and the status with respect to these covenants as of December 31, 2014 and 2013.
			Covenants			Actual Ratios at			Actual Ratios at
			Requirements			Dec. 31, 2014			Dec. 31, 2013
	Leverage ratio should be less than:1			.65 to 1			.432 to 1			.254 to 1
	Total outstanding debt as a percentage of total debt allowed based on the minimum timber market value covenant:2			—	2		74.94	%		48.24	%
	1	The leverage ratio is calculated as total debt divided by total capital. Total debt includes indebtedness for borrowed money, secured liabilities, obligations in respect of letters of credit, and guarantees. Total capital is the sum of total debt and net worth. Net worth is calculated as total assets minus total liabilities, as reflected on the balance sheet. This covenant is applied at the end of each quarter.
	2	Timber market value must be greater than 175 percent of total debt (as defined in (1) above). The timber market value is calculated by multiplying the average price received for sales of timber for the preceding four quarters by the current quarter’s ending inventory of timber. This covenant is applied at the end of the quarter on a rolling four-quarter basis.
	Based on management’s current operating projections, the Company believes it will remain in compliance with the debt covenants and have sufficient liquidity to finance operations and pay all obligations. However, depending on market conditions and should there be a return of economic uncertainties, the Company could request amendments, or waivers for covenants, or obtain refinancing in future periods. There can be no assurance that the Company will be able to obtain amendments or waivers or negotiate agreeable refinancing terms should it become necessary.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Note 11 – Income Taxes
	The components of income tax expense/(benefit) related to income from operations for the years ended December 31, 2014, 2013, and 2012 are as follows:
	(Thousands of dollars)	2014			2013			2012
	Federal
	Current	$	9,959			10,237			4,743
	Deferred		(961	)		138			(685	)
			8,998			10,375			4,058
	State
	Current		887			2,154			707
	Deferred		(292	)		103			36
			595			2,257			743
	Total income tax expense	$	9,593			12,632			4,801
	The following table provides a reconciliation of the Company’s income tax expense at the statutory U.S. federal rate of 35 percent to the actual income tax expense for the years ended December 31, 2014, 2013, and 2012.
	(Thousands of dollars)	2014			2013			2012
	U.S. federal income tax using statutory tax rate	$	10,239			13,588			4,913
	State tax, net of federal tax benefit		1,130			1,458			446
	Permanent differences		(1,000	)		(1,219	)		(558	)
	Tax effects resulting from:
	Gain on bargain purchase		—			(1,195	)		—
	Reversal of uncertain state income tax position		(776	)		—			—
	Income tax provision as reported	$	9,593			12,632			4,801
	The effective income tax rate in 2014 benefitted from the reversal of approximately $776,000 in uncertain state income tax liabilities that arose in 2010, due to the expiration of statute of limitations.
	The Company’s deferred tax assets and deferred tax liabilities at December 31, 2014 and 2013 consisted of the following:
	(Thousands of dollars)	2014			2013
	Deferred tax assets
	Investment in real estate held for development and sale	$	17,286			16,914
	Postretirement and other employee benefits		20,086			13,435
	Other deferred tax assets		2,093			2,360
	Total deferred tax assets		39,465			32,709
	Deferred tax liabilities
	Timber and timberlands		(27,191	)		(26,158	)
	Property, plant, and equipment		(11,021	)		(11,838	)
	Other deferred tax liabilities		(268	)		(326	)
	Total deferred tax liabilities		(38,480	)		(38,322	)
	Net deferred tax assets/(liabilities)	$	985			(5,613	)
	The deferred tax assets and liabilities are classified in the accompanying consolidated balance sheets as follows:
	(Thousands of dollars)	2014			2013
	Current tax assets	$	2,087			1,901
	Long-term tax liabilities		(1,102	)		(7,514	)
	Net deferred tax assets/(liabilities)	$	985			(5,613	)
	In assessing the realizability of deferred tax assets, Deltic’s management considers whether it is more-likely-than-not that some portion or all of the Company’s total deferred tax assets will not be realized. The ultimate realization of these deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. Based on the level of historical taxable income and projections for future taxable income over the periods in which the temporary differences are anticipated to reverse, management believes it is more-likely-than-not that the Company will realize the benefits of its deferred tax assets at December 31, 2014, as reductions of future taxable income or by utilizing available tax planning strategies. However, the amount of the net deferred tax assets considered realizable could be adjusted in the future if estimates of taxable income are revised.
	Unrecognized tax benefits represent potential future obligations to taxing authorities if uncertain tax positions the Company has taken, primarily on previously filed state income tax returns, are not sustained. Liabilities established for unrecognized tax benefits may not be combined with deferred tax assets or liabilities, except when offset by net operating losses.
	A reconciliation of the beginning and ending amount of unrecognized tax benefits (excluding both interest and any related federal benefits) is as follows:
	(Thousands of dollars)	2014			2013
	Balance at January 1	$	1,185			1,331
	Lapse of statute		(1,185	)		(146	)
	Balance at December 31	$	—			1,185
	The Company’s policy is to recognize interest expense related to unrecognized tax benefits in interest expense and penalties in other expenses. During the third quarter of 2014, the accrued liability balances for interest expense and the penalties related to the uncertain tax liabilities, mentioned above, were reversed and recognized as reductions to interest expense and an increase in other income, respectively. The Company had no liability accrued in deferred revenues and other accrued liabilities for interest and penalties related to uncertain tax liabilities at December 31, 2014, but had accrued approximately $621,000 at December 31, 2013. The Company is no longer subject to federal and state income tax examination by tax authorities for years before 2011.

Stockholders_Rights_Plan

Stockholders Rights Plan	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Stockholders Rights Plan	Note 12 – Stockholders Rights Plan
	The Company has a Stockholders Rights Plan (“Rights Plan”), which provides for each eligible common shareholder to receive a dividend of one preferred stock purchase right (a “Right”) for each outstanding share of the Company’s common stock held. On October 19, 2006, the Company’s Board of Directors amended the Rights Plan to, among other items, extend its term to December 31, 2016, and to increase the exercise price of the rights to $200 per share. The Rights will detach from the common stock and become exercisable: (1) following a specified period of time after the date of the first public announcement that a person or group of affiliated or associated persons (“Acquiring Person”) has become the beneficial owner of 15 percent or more of the Company’s common stock or (2) following a specified amount of time of the commencement of a tender or exchange offer by any Acquiring Person, which would, if consummated, result in such persons becoming the beneficial owner of 15 percent or more of the Company’s common stock. In either case, the detachment of the Rights from the common stock is subject to extension by a majority of the directors of the Company. The Rights have certain anti-takeover effects and will cause substantial dilution to any Acquiring Person that attempts to acquire the Company without conditioning the offer on a substantial number of Rights being acquired. Other terms of the Rights are set forth in, and the foregoing description is qualified in its entirety by, the Rights Agreement between the Company and Harris N.A. (formerly known as Harris Trust and Savings Bank), as Rights Agent.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Note 13 – Fair Value of Financial Instruments
	Fair value measurement accounting establishes a fair value hierarchy based on the quality of inputs used to measure fair value, with Level 1 being the highest quality and Level 3 being the lowest quality. Level 1 inputs are quoted prices in active markets on identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included in Level 1. Level 3 inputs are unobservable inputs which reflect assumptions about pricing by market participants.
	Information pertaining to the fair value of the pension plan assets is found in Note 16 – Employee and Retiree Benefit Plans.
	The following is a description of the valuation methodologies used for liabilities measured at fair value.
	Nonqualified Employee Savings Plan — Consists of mutual funds, which are valued at the net asset value of shares held by the plan at year-end, at quoted market prices.
	The fair value measurements for the Company’s financial liabilities accounted for at fair value on a recurring basis at December 31, 2014 are presented in the following table:
				Fair Value Measurements at Reporting Date Using
		December 31,		Quoted Prices in		Significant		Significant
				Active Markets for		Observable		Unobservable
				Identical		Inputs		Inputs
				Liabilities Inputs
	(Thousands of dollars)	2014		Level 1		Level 2		Level 3
	Liabilities
	Nonqualified employee savings plan	$	1,504		1,504		—		—
	Long-term Debt, Including Current Maturities — The fair value is estimated by discounting the scheduled debt payment streams to present value based on market rates for which the Company’s debt could be refinanced.
	The following table presents the carrying amounts and estimated fair values of financial instruments held by the Company at December 31, 2014 and 2013. The fair value of a financial instrument is the amount at which the instrument could be exchanged in a current transaction between willing parties. The table excludes financial instruments included in current assets and liabilities, except current maturities of long-term debt, all of which have fair values approximating carrying values.
		2014				2013
	(Thousands of dollars)	Carrying		Estimated		Carrying		Estimated
		Amount		Fair Value		Amount		Fair Value
	Financial liabilities
	Long-term debt, including current maturities	$	203,000		207,077		90,000		94,534

Concentration_of_Credit_Risks

Concentration of Credit Risks	12 Months Ended
	Dec. 31, 2014
Risks and Uncertainties [Abstract]
Concentration of Credit Risks	Note 14 – Concentration of Credit Risks
	Financial instruments, which potentially subject the Company to credit risk, are trade accounts receivable. These receivables normally arise from the sale of wood products, MDF, and real estate. Concentration of credit with respect to these trade accounts receivable is limited due to the large number of customers comprising the Company’s customer base. No single recurring customer accounted for a significant amount of the Company’s sales of wood products, MDF, or real estate in 2014, 2013, or 2012. At December 31, 2014 and 2013, there was no significant accounts receivable from a single customer. The Company performs ongoing credit evaluations of its customers and generally does not require collateral to support accounts receivable.

Other_Comprehensive_Income_Dis

Other Comprehensive Income Disclosures	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Other Comprehensive Income Disclosures	Note 15 – Other Comprehensive Income Disclosures
	The following tables detail the changes in accumulated other comprehensive loss (“AOCL”) by component for the twelve months ended December 31, 2014, 2013, and 2012:
	Changes in Accumulated Other Comprehensive Loss by Component (Net of Tax)
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	AOCL at January 1, 2014	$	(2,410	)		(482	)		213			(2,679	)
	Amounts reclassified from AOCL		111			173			(121	)		163
	Net loss arising during period		(5,316	)		(2,755	)		(824	)		(8,895	)
	Net current period other comprehensive loss		(5,205	)		(2,582	)		(945	)		(8,732	)
	AOCL at December 31, 2014	$	(7,615	)		(3,064	)		(732	)		(11,411	)
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	AOCL at January 1, 2013	$	(9,553	)		(3,380	)		(1,170	)		(14,103	)
	Amounts reclassified from AOCL		529			38			(116	)		451
	Net gain arising during period		6,614			2,860			1,499			10,973
	Net current period other comprehensive income		7,143			2,898			1,383			11,424
	AOCL at December 31, 2013	$	(2,410	)		(482	)		213			(2,679	)
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	AOCL at January 1, 2012	$	(8,124	)		(855	)		(750	)		(9,729	)
	Amounts reclassified from AOCL		608			226			(77	)		757
	Net loss arising during period		(2,037	)		(2,751	)		(343	)		(5,131	)
	Net current period other comprehensive loss		(1,429	)		(2,525	)		(420	)		(4,374	)
	AOCL at December 31, 2012	$	(9,553	)		(3,380	)		(1,170	)		(14,103	)
	Reclassification Out of Accumulated Other Comprehensive Loss
	Details about AOCL Components
		For the Year Ended December 31, 2014
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	Amortization of prior service costs	$	17			(7	)		—			10
	Amortization of actuarial losses		165			292			—			457
	Amortization of plan amendment		—			—			(199	)		(199	)
	Total before tax		182			285			(199	)		268
	Income tax benefit/(expense)		(71	)		(112	)		78			(105	)
	Total reclassifications – net of tax	$	111			173			(121	)		163
		For the Year Ended December 31, 2013
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	Amortization of prior service costs	$	18			(11	)		—			7
	Amortization of actuarial losses		852			74			8			934
	Amortization of plan amendment		—			—			(199	)		(199	)
	Total before tax		870			63			(191	)		742
	Income tax benefit/(expense)		(341	)		(25	)		75			(291	)
	Total reclassifications – net of tax	$	529			38			(116	)		451
	Amounts in parentheses indicate expenses. These items are included in the computation of net periodic retirement and postretirement costs. See Note 16 – Employee and Retiree Benefit Plans.
		For the Year Ended December 31, 2012
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
Retirement		Retirement			Plan
Plan		Plan
Amortization of prior service costs	$	18			(11	)		—			7
Amortization of actuarial losses		982			383			73			1,438
Amortization of plan amendment		—			—			(199	)		(199	)
Total before tax		1,000			372			(126	)		1,246
Income tax benefit/(expense)		(392	)		(146	)		49			(489	)
Total reclassifications – net of tax	$	608			226			(77	)		757
Amounts in parentheses indicate expenses. These items are included in the computation of net periodic retirement and postretirement costs. See Note 16 – Employee and Retiree Benefit Plans.
Tax Effects by Component
	For the Year Ended December 31, 2014
(Thousands of dollars)	Before			Tax			Net of
	Tax			(Expense)			Tax
	Amount			or Benefit			Amount
Gains/(losses) arising during the period	$	(14,636	)		5,741			(8,895	)
Amortization of prior service costs		10			(4	)		6
Amortization of actuarial losses/(gains)		457			(179	)		278
Amortization of plan amendment		(199	)		78			(121	)
	$	(14,368	)		5,636			(8,732	)
	For the Year Ended December 31, 2013
(Thousands of dollars)	Before			Tax			Net of
	Tax			(Expense)			Tax
	Amount			or Benefit			Amount
Gains/(losses) arising during the period	$	18,054			(7,081	)		10,973
Amortization of prior service costs		7			(3	)		4
Amortization of actuarial losses/(gains)		934			(366	)		568
Amortization of plan amendment		(199	)		78			(121	)
	$	18,796			(7,372	)		11,424
	For the Year Ended December 31, 2012
(Thousands of dollars)	Before			Tax			Net of
	Tax			(Expense)			Tax
	Amount			or Benefit			Amount
Gains/(losses) arising during the period	$	(8,442	)		3,311			(5,131	)
Amortization of prior service costs		7			(3	)		4
Amortization of actuarial losses/(gains)		1,438			(564	)		874
Amortization of plan amendment		(199	)		78			(121	)
	$	(7,196	)		2,822			(4,374	)

Employee_and_Retiree_Benefit_P

Employee and Retiree Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee and Retiree Benefit Plans	Note 16 – Employee and Retiree Benefit Plans
	The Company has a funded, qualified defined benefit retirement plan (“Retirement Plan”) that covers each employee of Deltic Timber Corporation, excluding employees of the subsidiaries, who completes 1,000 hours of service for a twelve-month period, once employment has commenced, and continues to meet both the 1,000 hours requirement and the employment requirement for each twelve-month period. An unfunded, nonqualified supplemental executive retirement plan is maintained for certain current and former employees. All contributions to both plans are made by the Company. The plans provide defined benefits based on years of benefit service and average monthly compensation as defined by the Company’s Retirement Plan. The Company determines the vested benefit obligation on the actuarial present value based on the employee’s expected date of retirement. For the December 31, 2014 measurement of Deltic’s defined benefit obligations, the Company selected the RP-2014 Mortality Tables as issued by the Society of Actuaries, since it was determined that those rates represented the best estimate of mortality for the participants in the Company’s plans. The Company also sponsors a plan for retired employees, excluding employees of the subsidiaries, that provides comprehensive healthcare benefits (supplementing Medicare benefits, for those eligible) and life insurance benefits. Costs are accrued for this plan during the service lives of covered employees. Retirees contribute a portion of the self-funded cost of healthcare benefits and the Company contributes the remainder. The Company pays premiums for life insurance coverage arranged through an insurance company. The health care plan is funded on a pay-as-you-go basis. The Company retains the right to modify or terminate the benefits and/or cost-sharing provisions.
	The following table sets forth the plans’ benefit obligations, fair value of plan assets, and funded status at December 31, 2014 and 2013.
		Defined Benefit						Defined Benefit						Other
		Funded						Unfunded						Postretirement
		Retirement						Retirement						Benefit
		Plan						Plan						Plan
	(Thousands of dollars)	2014			2013			2014			2013			2014			2013
	Change in benefit obligation
	Benefit obligation at beginning of period	$	37,010			42,716			4,690			9,299			10,756			12,542
	Service cost		1,476			1,549			302			143			418			450
	Interest cost		1,839			1,557			373			192			497			431
	Participant contributions		—			—			—			—			88			88
	Actuarial (gain)/loss		8,626			(7,672	)		4,534			(4,705	)		1,355			(2,466	)
	Benefits paid		(1,201	)		(1,140	)		(255	)		(239	)		(416	)		(289	)
	Benefit obligation at end of period	$	47,750			37,010			9,644			4,690			12,698			10,756
	Change in plan assets
	Fair value of plan assets at beginning of period	$	30,627			25,463			—			—			—			—
	Actual return on plan assets		2,327			5,237			—			—			—			—
	Employer contributions		1,200			1,200			255			239			328			201
	Participant contributions		—			—			—			—			88			88
	Benefits paid		(1,201	)		(1,140	)		(255	)		(239	)		(416	)		(289	)
	Expenses		(158	)		(133	)		—			—			—			—
	Fair value of plan assets at end of period	$	32,795			30,627			—			—			—			—
	Funded status of plans	$	(14,955	)		(6,383	)		(9,644	)		(4,690	)		(12,698	)		(10,756	)
	Amounts recognized in the balance sheet
	Current liability	$	—			—			(272	)		(233	)		(355	)		(365	)
	Noncurrent liability	$	(14,955	)		(6,383	)		(9,372	)		(4,457	)		(12,343	)		(10,391	)
	Deferred income taxes – net	$	5,866			2,504			3,783			1,840			4,981			4,219
	Accumulated other comprehensive (income)/loss	$	7,615			2,410			3,064			482			732			(213	)
	Amounts recognized in accumulated other comprehensive loss
	Net unrecognized (gain)/loss	$	12,525			3,942			5,041			799			1,231			(124	)
	Unrecognized prior service cost/(credit)		4			21			—			(7	)		(46	)		(245	)
	Tax effects		(4,914	)		(1,553	)		(1,977	)		(310	)		(453	)		156
		$	7,615			2,410			3,064			482			732			(213	)
		Defined Benefit						Defined Benefit						Other
		Funded						Unfunded						Postretirement
		Retirement						Retirement						Benefit
		Plan						Plan						Plan
	(Thousands of dollars)	2014			2013			2014			2013			2014			2013
	Assumptions used in measurement of benefit obligations
	Weighted average discount rate		4.21	%		4.84	%		4.21	%		4.84	%		4.25	%		4.85	%
	Rate of compensation increase		4	%		4	%		4	%		4	%		N/A			N/A
	Accumulated benefit obligations at year end	$	40,720			32,272			6,792			4,660			N/A			N/A
	Components of net periodic retirement expense and other postretirement benefits expense consisted of the following:
	(Thousands of dollars)	2014			2013			2012
	Defined benefit funded retirement plan
	Service cost	$	1,476			1,549			1,630
	Interest cost		1,839			1,557			1,622
	Expected return on plan assets		(2,290	)		(1,894	)		(1,692	)
	Amortization of prior service cost		17			18			18
	Amortization of actuarial loss		165			852			982
	Net periodic benefit cost	$	1,207			2,082			2,560
	Defined benefit unfunded retirement plan
	Service cost	$	302			143			364
	Interest cost		373			193			355
	Amortization of prior service credit		(7	)		(11	)		(11	)
	Amortization of actuarial loss		292			74			383
	Net periodic benefit cost	$	960			399			1,091
	Other postretirement benefit plan
	Service cost	$	418			450			455
	Interest cost		497			431			467
	Amortization of prior service credit		(199	)		(199	)		(199	)
	Amortization of actuarial loss		—			8			73
Net periodic benefit cost	$	716			690			796
(Thousands of dollars)	2014			2013			2012
Assumptions used to determine net periodic benefit cost – defined benefit pension plans
Weighted average discount rate		4.84	%		3.94	%		4.34	%
Expected long-term rate of return on plan assets		7.5	%		7.5	%		7.5	%
Rate of compensation increase		4	%		4	%		4	%
Assumptions used to determine net periodic benefit cost – other postretirement plan
Weighted average discount rate		4.85	%		3.9	%		4.3	%
Other changes in plan assets and benefit obligations recognized in other comprehensive (income)/loss
Net unrecognized loss/(gain)	$	14,636			(18,054	)		8,442
Amortization of prior service credit		(10	)		(7	)		(7	)
Amortization of actuarial losses		(457	)		(934	)		(1,438	)
Amortization of plan amendment		199			199			199
Tax effect of changes		(5,636	)		7,372			(2,822	)
Total recognized in other comprehensive (income)/loss	$	8,732			(11,424	)		4,374
(Thousands of dollars)	Defined			Defined			Other
	Benefit			Benefit			Post-
	Funded			Unfunded			Retirement
	Retirement			Retirement			Benefit
	Plan			Plan			Plan
Estimated benefit payments by year
2015	$	1,351			272			355
2016		1,421			270			369
2017		1,535			267			405
2018		1,668			264			447
2019		1,835			261			498
2020 - 2024		12,359			2,849			3,180
The estimated net loss and net prior service cost for the defined benefit funded and unfunded retirement pension plans that will be amortized from accumulated other comprehensive income into net periodic benefit cost over the next fiscal year are $1,136,000 and $4,000, respectively. The plan amendment for the other defined benefit postretirement plans that will be amortized from accumulated other comprehensive income into net periodic benefit cost over the next fiscal year is $46,000.
The amount of projected expense of the defined benefit funded retirement plan is expected to be $2,148,000 for 2015. The Company expects to make contributions during 2015 of approximately $1,200,000 to the defined benefit funded retirement plan, $272,000 to fund benefits paid from its defined benefit unfunded retirement plan, and approximately $355,000 to fund the other postretirement benefit plan.
The discount rate assumption used by the Company to measure benefit obligations and net periodic expenses is based on a spot-rate yield curve using current market data for corporate bonds at the measurement date and is used to determine the present value of the expected future cash flows at the measurement date. Additionally, a single rate is determined so that the present value of the benefit obligations using the single rate equals the present value using the spot rate yield curve. The yield curve only includes bonds that meet the following criteria: (1) have maturities between 6 months and 30 years; (2) are noncallable, nonputable, and do not have a sinking fund provision; (3) have fixed coupon payments with a single payment at maturity; (4) have more than $250 million par outstanding; (5) are U.S. dollar-denominated bonds; and (6) have an average rating of AA- (S&P/Fitch) or Aa3 (Moody’s) and higher.
To develop the expected long-term rate of return on asset assumption, the Company considered the rates of return of assets the Company’s pension plan invested in and compared them to the historical rates of return on investments in similar assets. Further, these returns were compared to plans of other companies which had similar investment philosophies. After a review of the rate of inflation and its impact, management made the selection of the 7.50 percent assumption.
In determining the benefit obligation for health care at December 31, 2014, health care inflation cost was assumed to increase at an annual rate of five percent in 2014. Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plan. A one percentage-point increase in the assumed health care cost trend rate would increase the aggregate service and interest cost components of periodic benefit cost for 2014 by $172,000 and the benefit obligation by $2,171,000, while a one percentage-point decrease in the assumed rate would decrease the 2014 cost components by $135,000 and the benefit obligation by $1,713,000.
Funded Plan — The assets of the defined benefit funded retirement plan (the “Plan”) are contained in a trust, sponsored by Deltic, and administered by a trustee appointed by the Company’s Pension Investment and Employees Benefits Committee.
The investment policy of the Plan is to achieve growth with the preservation of principal. To achieve the goal of growth of plan assets (excluding contributions and withdrawals) at a rate that exceeds inflation, a balanced portfolio consisting of equities, fixed income, alternative investments, and cash equivalents is maintained. The components of the portfolio should be securities that have readily available prices and can be sold easily without significantly impacting the price of the securities, with an exception for professionally managed hedge funds. The minimum and maximum asset allocation levels in total, are equities, 45 to 70 percent, fixed income, 25 to 55 percent, alternative investments, zero to 15 percent, and up to 5 percent in cash equivalents. Further, the total equity minimum and maximum allocation levels at market, for large cap equity is 40 to 60 percent, mid and small cap equity is 5 to 15 percent, and international equity is zero to 25 percent, with international emerging not to exceed 40 percent of international equities allocation.
Not more than 2.5 percent of the market value of Plan assets may be held in the securities of any single issuer with the exception of the U.S. government or its agencies. As of December 31, 2014,
less than three percent of the total market value of the Plan assets was invested in collateralized mortgage obligations and asset-backed security issues.
The following types of securities are permitted in the Plan:
Equities	–		Common stocks, preferred stocks, convertible preferred stocks, convertible bonds, American depository receipts, proprietary funds, mutual funds, and exchange-traded funds.
Fixed income	–		U.S. government securities, corporate debt obligations, U.S. government agency securities, mortgage-backed security issues, international bonds, and asset-backed securities.
Cash equivalents	–		U.S. government securities.
Alternative investments, hedge funds	–		Qualified fund of funds limited partnership shares or fund of funds in a mutual fund wrapper.
Fair Value Measurement — Following is a description of the valuation methodologies used for retirement plan assets measured at fair value.
Common stock, preferred securities, and exchange-traded funds: Valued at the closing price reported on the active market on which the individual securities are traded.
Mutual funds: Valued at the net asset value (“NAV”) of shares held by the Plan at year-end, at quoted market prices.
Alternative investment funds: Valued by company or industry source.
U.S. treasuries and government agency securities: Valued using quoted prices for similar assets in active markets.
Corporate debt obligations and U.S. government and agency securities: Valued using pricing models that utilize trade, bid, and other market information; or benchmark curves, benchmarking of like securities, sector groupings, and matrix pricing.
Money market funds: Valued at par, which approximates fair value.
The methods described above may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Plan believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.
Fair value measurement accounting establishes a fair value hierarchy based on the quality of inputs used to measure fair value, with Level 1 being the highest quality and Level 3 being the lowest quality. Level 1 inputs are quoted prices in active markets on identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included in Level 1. Level 3 inputs are unobservable inputs which reflect assumptions about pricing by market participants.
The following table sets forth by level within the fair value hierarchy the Plan’s investments at fair value as of December 31, 2014.
	Fair Value Measurements at Reporting Date Using
(Thousands of dollars)	Percent			Total			Level 1			Level 2			Level 3
	of			Carrying
	Total			Value at
				Dec. 31,
				2014
Plan Investments
Cash and cash equivalents		4.5		$	1,470			1,470			—			—
Other		0.1			40			40			—			—
Equity securities by sector:
Energy		0.3			105			105			—			—
Materials and industrials		2			652			652			—			—
Consumer		3.9			1,274			1,274			—			—
Health care		2.6			854			854			—			—
Financials		0.6			201			201			—			—
Information tech		4.6			1,503			1,503			—			—
Foreign stocks		1			319			319			—			—
U.S. Govt. and agency securities		15.2			5,001			3,208			1,793			—
Corporate debt obligations		7.2			2,370			—			2,370			—
Mutual funds:
Dividends and growth		28.4			9,327			9,327			—			—
International and emerging markets		5.6			1,835			1,835			—			—
Fixed income		2.3			742			742			—			—
Exchange-traded funds		15			4,913			4,913			—			—
Alternative investment funds		6.7			2,189			—			—			2,189
Total plan investments at fair value		100		$	32,795			26,443			4,163			2,189
Percent of fair value hierarchy					100			80.6			12.7			6.7
The following table sets forth the activity in the Level 3 investments for the year ended December 31, 2014.
	Fair Value Measurements
	Using Significant
	Unobservable Inputs
	(Level 3)
(Thousands of dollars)	Alternative Investment
	Funds
Beginning balance at December 31, 2013	$	2,077
Actual return on plan assets:
Relating to assets still held at the reporting date		112
Purchases, sales, and settlements		—
Ending balance at December 31, 2014	$	2,189
The following table sets forth by level within the fair value hierarchy the Plan’s investments at fair value as of December 31, 2013.
	Fair Value Measurements at Reporting Date Using
(Thousands of dollars)	Percent			Total			Level 1			Level 2			Level 3
	of			Carrying
	Total			Value at
				Dec. 31,
				2013
Plan Investments
Cash and cash equivalents		3.2		$	984			984			—			—
Other		0.2			54			54			—			—
Equity securities by sector:
Energy		0.4			111			111			—			—
Materials and industrials		2.6			784			784			—			—
Consumer		4.7			1,435			1,435			—			—
Health care		2.5			771			771			—			—
Financials		0.8			259			259			—			—
Information tech		4.6			1,409			1,409			—			—
Foreign stocks		1			302			302			—			—
U.S. Govt. and agency securities		12.3			3,775			1,633			2,142			—
Corporate debt obligations		10.7			3,287			—			3,287			—
Mutual funds:
Dividends and growth		29.5			9,042			9,042			—			—
International and emerging markets		5.9			1,798			1,798			—			—
Exchange-traded funds		14.8			4,539			4,539			—			—
Alternative investment funds		6.8			2,077			—			—			2,077
Total plan investments at fair value		100		$	30,627			23,121			5,429			2,077
Percent of fair value hierarchy					100			75.5			17.7			6.8
The following table sets forth the activity in the Level 3 investments for the year ended December 31, 2013.
	Fair Value Measurements
	Using Significant
	Unobservable Inputs
	(Level 3)
(Thousands of dollars)	Alternative Investment
	Funds
Beginning balance at December 31, 2012	$	—
Actual return on plan assets:
Relating to assets still held at the reporting date		77
Purchases, sales, and settlements		2,000
Ending balance at December 31, 2013	$	2,077
Thrift Plan — Employees of the Company may participate in its thrift plan by allotting up to a specific percentage of their base pay. The Company matches contributions at a stated percentage of each employee’s allotment. Company contributions to this plan were $829,000 in 2014, $792,000 in 2013, and $584,000 in 2012.

Incentive_Plans

Incentive Plans	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Incentive Plans	Note 17 – Incentive Plans
	Stock Incentive Plan
	On April 26, 2012, the Company’s shareholders approved an amendment to extend the Deltic Timber Corporation 2002 Stock Incentive Plan (“the 2002 Plan”) for ten years to April 26, 2022 and change the maximum number of shares which may be awarded in any calendar year as restricted stock and restricted stock units or other stock-based awards to 75,000 shares. The 2002 Plan replaced the 1996 Stock Incentive Plan, which was terminated. The 2002 Plan permits annual awards of shares of the Company’s common stock to executives, other key employees, and nonemployee directors. Under the plan, the Executive Compensation Committee (“the Committee”) is authorized to grant: (1) stock options; (2) restricted stock and restricted stock units; (3) performance units; and (4) other stock-based awards, including stock appreciation rights and rights to dividends and dividend equivalents. The number of shares originally registered for issuance under the 2002 Plan was 1,800,000 shares. Additional shares may be issued if an adjustment is determined necessary by the Committee as the result of dividend or other distribution, recapitalization, stock split, reverse stock split, reorganization, merger, consolidation, split-up, spin-off, combination, repurchase or exchange of common stock, or other corporate transaction in order to prevent dilution or enlargement of benefits or potential benefits intended to be made available. At December 31, 2014, 845,118 of these 1,800,000 shares were available for award under the 2002 Plan. No participant in the 2002 Plan may receive options and stock appreciation rights in any calendar year that relates to more than 50,000 shares, and the maximum number of shares, which may be awarded as restricted stock and restricted stock units or other stock-based awards, is 75,000 shares. The Company has a policy of issuing treasury stock to satisfy all share-based incentive plans.
	Under the fair value recognition provisions for share-based payments, share-based compensation cost is estimated at the grant date based on the fair value of the award and is recognized as expense over the requisite service period of the award. The fair value of stock options granted is determined using a binomial model. The fair value of restricted stock awards is determined by reference to the fair market value of the Company’s common stock on the date of grant. Restricted stock performance units are valued using a Monte Carlo simulation model. Compensation cost is recognized on a straight-line basis over the requisite service period. The benefits of tax deductions in excess of recognized compensation cost is to be reported as a financing cash flow.
	Deltic issues restricted stock performance units whose vesting is contingent upon meeting certain financial performance goals based upon the Company’s total stockholder return compared to the total return of a Paper and Forest Products Index selected by the Committee and calculated by Standard and Poor’s. Determining the appropriate amount to expense is based on likelihood of achievement of the stated goals and requires judgment, including forecasting future financial results.
	The expected option term is based on the term of the option and historical exercise and expiration experience. The Company uses historical volatility over a ten-year trading life to determine weighted expected volatility assumptions. The expected dividend yield is based on the Company’s average dividend yield from 2010 to 2013. Risk-free interest rates are based on historical rates and forward-looking factors. The pre-vesting forfeiture rate is based on past forfeiture rates and expected trends.
	Assumptions for the 2014, 2013, and 2012 valuation of stock options and restricted stock performance units consisted of the following:
		2014			2013			2012
	Expected term of options (in years)		6.27			6.27			6.27
	Weighted expected volatility		37.38	%		37.78	%		38.78	%
	Dividend yield		0.55	%		0.58	%		0.61	%
	Risk-free interest rate - performance restricted shares		1.23	%		0.6	%		0.6	%
	Risk-free interest rate - stock options		2.99	%		1.98	%		2	%
	Stock price as of valuation date	$	63.21			71.35			67.67
	Restricted performance share valuation	$	80.56			87.74			90.61
	Grant date fair value - stock options	$	21.87			26.2			24.92
	The consolidated statements of income for the years ended December 31, 2014, 2013, and 2012 included $3,238,000, $2,797,000, and $2,298,000, respectively, of stock-based compensation expense reflected in general and administrative expenses. The potential excess income tax benefit derived from all share-based payment arrangements with employees was $160,000, $409,000, and $607,000 for the years ended December 31, 2014, 2013, and 2012, respectively.
	Stock Options — For each option granted under the 2002 Plan, the Committee fixes the option price at not less than fair market value on the date of the grant and the option term, not to exceed ten years from date of grant. Options granted after 1998 have been issued with terms of ten years and are nonqualified. For all options granted since 2003, one-fourth vest after each one-year period over the subsequent four years from issuance. The resulting fixed stock-based compensation cost was recognized over the vesting period for these options. All outstanding options have an option price not less than the market value on the grant date, with a range in option prices of $34.41 to $71.35 per share.
	A summary of stock options as of December 31, 2014, and changes during the year ended are presented below:
		Shares			Weighted			Weighted			Aggregate
					Average			Average			Intrinsic
					Exercise			Remaining			Value
					Price			Contractual			$0
								Term (Years)
	Outstanding at January 1, 2014		131,456		$	59.64
	Granted		26,611			63.35
	Exercised		(5,854	)		43.3
	Forfeited/expired		(460	)		36.61
	Outstanding at December 31, 2014		151,753		$	60.99			6.1		$	1,197
	Exercisable at December 31, 2014		87,552		$	56.96			4.6		$	1,020
	The intrinsic value of options exercised during the years ended December 31, 2014, 2013, and 2012 was $124,000, $513,000, and $682,000, respectively. At December 31, 2014, there was $966,000 of unrecognized compensation cost related to nonvested stock options. The weighted average period remaining to vest is 1.6 years.
	Additional information about stock options outstanding at December 31, 2014, consisted of the following:
		Options Outstanding									Options Exercisable
	Range of Exercise Prices	Number			Average			Average			Number		Average
		of			Life in			Exercise			of		Exercise
		Options			Years			Price			Options		Price
	$31.00—$35.00		2,766			4.1		$	34.41			2,766	$	34.41
	$41.00—$45.00		14,020			5.1		$	44.84			14,020	$	44.84
	$51.00—$55.00		31,848			1.9		$	53.01			31,848	$	53.01
	$56.00—$65.00		52,462			7.6		$	63.38			19,727	$	63.54
	$66.00—$75.00		50,657			7.6		$	69.45			19,191	$	68.85
			151,753									87,552
	Restricted Stock and Restricted Stock Units — The Committee may grant restricted stock and restricted stock units to selected employees, with conditions to vesting for each grant established by the Committee. During the vesting period, the grantee may vote and receive dividends on the shares, but shares are subject to transfer restrictions and are all, or partially, forfeited if a grantee terminates, depending on the reason. Restricted stock and restricted stock units granted since 2003 have vested after four years, and the stock-based compensation is recognized on a straight-line basis over the requisite service period for the entire award.
	A summary of nonvested restricted stock as of December 31, 2014, and changes during the year then-ended are presented below:
		Shares			Weighted
					Average
					Grant-Date
					Fair Value
	Nonvested at January 1, 2014		79,591		$	62.31
	Granted		24,951			63.3
	Vested		(19,132	)		44.84
	Nonvested at December 31, 2014		85,410		$	66.51
	As of December 31, 2014, there was $2,453,000 of unrecognized compensation cost related to nonvested restricted stock. That cost is expected to be recognized over a weighted-average period of 1.7 years.
	Performance Units — Performance units granted under the 2002 Plan may be denominated in cash, common shares, other securities, other awards allowed under the 2002 Plan, or other property and shall confer on the holder thereof rights valued as determined by the Committee and payable to, or exercisable by, the holder, in whole or in part, upon achievement of such performance goals during such performance periods as the Committee shall establish. Subject to the terms of the 2002 Plan, the performance goals to be achieved during any performance period, the length of any performance period, the amount of any performance unit granted, and any payment or transfer to be made pursuant to any performance unit shall be determined by the Committee. During 2014, 2013, and 2012, the Company issued performance units in the form of restricted stock with specified performance requirements. During the vesting period, the grantee may vote and receive dividends on the shares, but shares are subject to transfer restrictions and are all, or partially, forfeited if a grantee terminates, depending on the reason. Performance units granted since 2003 have vested after four years, and the stock-based compensation is recognized on a straight-line basis over the requisite service period for the entire award. During 2014 and 2013, the performance shares granted in 2010 and 2009, respectively, did not meet vesting conditions and were returned to treasury stock.
	A summary of nonvested restricted stock performance units as of December 31, 2014, and changes during the year then-ended are presented below:
		Shares			Weighted
					Average
					Grant-Date
					Fair Value
	Nonvested at January 1, 2014		52,625		$	80.87
	Granted		16,613			80.7
	Units not meeting vesting conditions		(12,652	)		58.66
	Nonvested at December 31, 2014		56,586		$	85.78
	As of December 31, 2014, there was $2,083,000 of unrecognized compensation cost related to nonvested restricted stock performance units. That cost is expected to be recognized over a weighted-average period of 1.7 years.
Other Stock-Based Awards — The Committee may also grant other awards, including but not limited to, stock appreciation rights and rights to dividends and dividend equivalents that are denominated, or payable in, valued in whole or in part by reference to, or otherwise based on or related to shares of the Company’s common stock, including securities convertible in its common stock, as deemed by the Committee to be consistent with the purpose of the 2002 Plan. No such other stock-based awards have been granted.
Cash Incentive Compensation Plan
The Company has an incentive compensation plan that provides for annual cash awards to officers and key employees based on actual results for a year compared to objectives established at the beginning of that year by the Executive Compensation Committee, which administers the Plan. The Company recorded expenses for cash incentive awards of $586,000, $2,549,000, and $2,014,000 in 2014, 2013, and 2012, respectively. The Company had accrued provisions for cash incentive awards totaling $400,000 and $2,631,000 at December 31, 2014 and 2013, respectively, reflected in the consolidated balance sheets in deferred revenues and other accrued liabilities.

Supplemental_Cash_Flows_Disclo

Supplemental Cash Flows Disclosures	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flows Disclosures	Note 18 – Supplemental Cash Flows Disclosures
	Additional information concerning cash flows at December 31 consisted of the following:
	(Thousands of dollars)	2014			2013			2012
	Income taxes paid in cash	$	14,976			11,042			4,227
	Interest paid		5,420			3,954			3,571
	Interest capitalized		(70	)		(53	)		(36	)
	Non-cash investing and financing activities excluded from the Consolidated Statement of Cash Flows include:
	(Thousands of dollars)	2014			2013			2012
	Issuance of restricted stock	$	1,290			935			1,393
	Capital expenditures accrued, not paid		738			1,271			79
	Fair value of Del-Tin Fiber net assets acquired		—			19,369			—
	(Increases)/decreases in operating working capital, other than cash and cash equivalents, for each of the three years ended December 31 consisted of the following:
	(Thousands of dollars)	2014			2013			2012
	Trade accounts receivable	$	(1,756	)		2,178			(457	)
	Other receivables		8			(6	)		(12	)
	Inventories		945			(2,740	)		(541	)
	Prepaid expenses and other current assets		(2,543	)		(184	)		963
	Trade accounts payable		(2,123	)		3,701			35
	Accrued taxes other than income taxes		(61	)		216			(19	)
	Deferred revenues and other accrued liabilities		(3,644	)		2,718			2,486
		$	(9,174	)		5,883			2,455
	Cash flows provided by other operating activities included a decrease in deferred long-term mineral lease rental revenue of $266,000 in 2014, $1,635,000 in 2013, and $1,767,000 in 2012. Total cash payments received were $711,000 in 2014, $30,000 in 2013, and $450,000 in 2012. These payments will be recognized over the term of the lease.

Earnings_per_Share

Earnings per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings per Share	Note 19 – Earnings per Share
	The amounts used in computing earnings per share and the effect on income and weighted-average number of shares outstanding of dilutive potential common stock consisted of the following at December 31:
	(Thousands of dollars, except per share amounts)	2014		2013		2012
	Net earnings allocated to common stock	$	19,445		25,924		9,144
	Net earnings allocated to participating securities		217		268		91
	Net income allocated to common stock and participating securities	$	19,662		26,192		9,235
	Weighted average number of common shares used in basic EPS		12,497		12,566		12,525
	Effect of dilutive stock awards		56		58		63
	Weighted average number of common shares and dilutive potential common stock used in EPS assuming dilution		12,553		12,624		12,588
	Earnings per common share
	Basic	$	1.56		2.06		0.73
	Assuming dilution	$	1.55		2.05		0.73
	Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of common stock equivalents using the treasury stock method.
	The following table provides information about potentially dilutive securities that were outstanding but were not included in the computation of diluted earnings per share, because they were anti-dilutive or, in the case of the restricted performance shares, did not meet the metrics established for awarding:
		2014		2013		2012
	Options		76,968		50,197		26,459
	Restricted performance shares		56,586		52,625		29,831

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 20 – Commitments and Contingencies
	Commitments — Commitments for capital expenditures at December 31, 2014 were approximately $5,717,000 for property, plant, and equipment; and $11,479,000 for investment in real estate held for development and sale.
	The Company is also involved in litigation incidental to its business from time to time. Currently, there are no material legal proceedings outstanding.

Gain_on_Involuntary_Conversion

Gain on Involuntary Conversion	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Gain on Involuntary Conversion	Note 21 – Gain on Involuntary Conversion
	In December of 2012, four lumber storage sheds at the Company’s Ola Mill were destroyed due to an accumulation of snow and ice on their roofs. Insurance policies covered the replacement cost of these sheds, subject to deductibles. The Company received a total of $881,000 in payments from the insurance company for the year ended December 31, 2013. These payments were reported in operating income as a gain on involuntary conversion in the Consolidated Statements of Income and were used to fund capital expenditures to replace the storage sheds.

Business_Segments

Business Segments	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Business Segments	Note 22 – Business Segments
	The Company’s four reporting segments consist of Deltic’s three operating business units and its corporate function. Each reporting entity has a separate management team and infrastructure that offers different products and/or services.
	Woodlands operations manage the Company’s Southern Pine timberlands located primarily in Arkansas and north Louisiana and derive revenue from the harvest of timber from the timberlands in accordance with its harvest plans, and either sells timber to third parties in the domestic market or to the Company’s sawmills for conversion into lumber. In addition, this segment may, from time to time, identify and sell a portion of its timberland holdings that are either non-strategic to future timberland management activities or that have appreciated, due primarily to location, to a level that exceeds its value as a timber-growing asset. This segment also generates revenue from oil and gas royalties and the leasing of hunting, oil and gas, and other rights on its timberlands.
	The Manufacturing segment consists of Deltic’s two sawmills which convert timber into lumber and Del-Tin Fiber, a plant which converts sawmill residuals and an adhesive bond into MDF. The sawmills purchase timber from third parties or the Company’s Woodlands segment. The MDF plant purchases sawmill residuals from third parties and from the Company’s sawmills. The mills produce a variety of products, including dimension lumber, boards, and timbers, while the MDF plant produces several different grades of MDF. These products are sold primarily to wholesale distributors, large retailers, lumber treaters, industrial accounts, and truss manufacturers in the South and Midwest and are used in residential construction, roof trusses, remanufactured products, laminated beams, cabinets, flooring, and door parts.
	The Real Estate operations, which include four real estate developments, add value to former legacy timberland by developing it into upscale, planned residential and commercial developments. These developments, which are generally centered on a core amenity, are being developed in stages. Historically, real estate sales have consisted primarily of residential lots sold to builders or individuals, commercial site sales, and sales of undeveloped acreage. In addition, this segment currently leases retail and office space to third parties in a retail center constructed by the Company, and held for sale, in one of its developments. This segment also manages: (1) a real estate brokerage subsidiary which generates commission revenue by reselling existing homes and (2) a country club operation, Chenal Country Club, Inc., around which the Company’s Chenal Valley development is centered. This club operation derives its revenues from membership services, food and beverage sales, and membership dues.
	Corporate operations consist primarily of senior management, accounting, information systems, human resources, purchasing, treasury, income tax, and legal staff functions that provide support services to the operating business units. The Company currently does not allocate the cost of maintaining these support functions to its operating units.
	The accounting policies of the reportable segments are the same as those described in Note 1 – Significant Accounting Policies. The Company evaluates the performance of its segments based on operating income before results of: any equity method investee; interest income and expense; other non-operating income or expense; and income taxes. Intersegment revenues consist primarily of timber sales from the Woodlands segment to the sawmills’ operations (part of the Manufacturing segment) and are transferred at rates that approximate market for the respective operating area.
	Information about the Company’s business segments consisted of the following:
	(Thousands of dollars)		2014			2013			2012
	Net sales
	Woodlands		$	37,008			33,834			37,285
	Manufacturing2			189,561			167,955			105,956
	Real Estate			16,283			11,734			10,992
	Eliminations1			(15,497	)		(13,821	)		(13,325	)
			$	227,355			199,702			140,908
	Income before income taxes
	Operating income/(loss)
	Woodlands		$	19,113			16,749			18,374
	Manufacturing2			31,440			38,496			18,083
	Real Estate			1,115			(1,430	)		(2,099	)
	Corporate			(17,405	)		(17,994	)		(17,394	)
	Eliminations			133			(158	)		168
	Operating income			34,396			35,663			17,132
	Equity in earnings of Del-Tin Fiber2			—			1,084			959
	Interest income			5			13			17
	Interest and other debt expense, net of capitalized interest			(5,430	)		(4,578	)		(4,092	)
	Gain on bargain purchase			—			3,413			—
	Other income			284			3,229			20
			$	29,255			38,824			14,036
	Total assets at year-end
	Woodlands		$	363,436			247,156			240,026
	Manufacturing2			80,023			85,837			30,136
	Real Estate			57,646			59,549			58,783
	Corporate3,4			26,164			18,802			24,264
			$	527,269			411,344			353,209
	Depreciation, amortization, and cost of fee timber harvested
	Woodlands		$	5,765			4,785			4,786
	Manufacturing2			12,147			9,910			5,378
	Real Estate			355			343			374
	Corporate			75			93			104
			$	18,342			15,131			10,642
	Capital expenditures5
	Woodlands		$	4,038			3,836			4,026
	Manufacturing2			12,311			16,532			2,478
	Real Estate			3,934			4,267			2,996
	Corporate			49			14			7
			$	20,332			24,649			9,507
	Timberland acquisition expenditures5		$	118,203			8,919			14,527
		1	Primarily intersegment sales of timber from Woodlands to Manufacturing.
		2	Del-Tin Fiber became a consolidated subsidiary, reported in the Manufacturing segment, upon acquisition of a controlling interest of its ownership effective April 1, 2013.
		3	Includes investment in Del-Tin Fiber, an equity method investee, of $6,293,000 at December 31, 2012. (For additional information, see Note 4 – Business Combinations.)
		4	Includes balance of timberland sale proceeds held by trustee, and there were none as of December 31, 2014 and 2013 and $7,000 as of December 31, 2012.
		5	Some 2013 and 2012 amounts have been reclassified to conform to the 2014 presentation.

Financial_Results_by_Quarter_U

Financial Results by Quarter (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Financial Results by Quarter (Unaudited)	Note 23 – Financial Results by Quarter (Unaudited)
	(Thousands of dollars, except per share amounts)
			2014
			First		Second		Third		Fourth		Year
			Quarter		Quarter		Quarter		Quarter
	Net sales		$	55,379		58,605		58,301		55,070		227,355
	Gross profit			13,930		14,455		14,046		10,447		52,878
	Operating income			8,807		9,734		8,782		7,073		34,396
	Net income			4,911		5,298		5,974		3,479		19,662
	Earnings per common share
	Basic		$	0.39		0.42		0.47		0.28		1.56
	Assuming dilution			0.39		0.42		0.47		0.28		1.55
	Dividends paid per common share2		$	0.1		0.1		0.1		0.1		0.4
			2013
			First		Second		Third		Fourth		Year
			Quarter		Quarter		Quarter		Quarter
	Net sales		$	41,563		53,247		56,520		48,372		199,702
	Gross profit			15,384		14,648		14,810		8,977		53,819
	Operating income			10,548		10,991		9,599		4,525		35,663
	Net income1			6,774		11,268		5,813		2,337		26,192
	Earnings per common share
	Basic		$	0.53		0.89		0.46		0.18		2.06
	Assuming dilution			0.53		0.88		0.46		0.18		2.05
	Dividends paid per common share2		$	0.1		0.1		0.1		0.1		0.4
	(Thousands of dollars, except per share amounts)
			2012
			First		Second		Third		Fourth		Year
			Quarter		Quarter		Quarter		Quarter
	Net sales		$	30,639		37,105		36,499		36,665		140,908
	Gross profit			5,730		10,205		10,237		9,388		35,560
	Operating income			1,134		6,259		5,104		4,635		17,132
	Net income			97		3,516		3,218		2,404		9,235
	Earnings per common share
	Basic		$	0.01		0.28		0.25		0.19		0.73
	Assuming dilution			0.01		0.28		0.25		0.19		0.73
	Dividends paid per common share2		$	0.075		0.075		0.075		0.075		0.3
	1	Del-Tin Fiber, formerly an equity investment, became a consolidated subsidiary effective April 1, 2013. Net income for the second quarter of 2013 includes a gain on bargain purchase of $3,285,000 and a gain on previously held equity investment of $3,165,000. The fourth quarter of 2013 includes additional bargain gain recognized of $128,000, for a total of $3,413,000 for the 2013 year. (For additional information, see Note 4 – Business Combinations.)
	2	Payment of dividends is the means by which Deltic Timber Corporation makes distributions to its shareholders of profits and cash flows generated by the Company’s business operations. These dividends are declared by the Company’s Board of Directors on a quarterly basis. The Company’s dividend strategy is to grow the amount of the dividend over time, at a rate of increase that is believed to be sustainable. The timing and amount of future increases are based on the estimated trend for future earnings and cash flows, taking into account other potential uses of the Company’s capital resources including, but not limited to, acquisition opportunities, capital expenditures for existing operations, debt repayments, and repurchases of the Company’s common stock.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Description of Business	Description of Business — Deltic Timber Corporation (“Deltic” or the “Company”) is a natural resources company engaged primarily in the growing and harvesting of timber and the manufacturing and marketing of lumber and medium density fiberboard (“MDF”). Deltic owns approximately 530,000 acres of timberland, primarily in Arkansas and north Louisiana. The Company’s sawmill operations are located at Ola in central Arkansas and at Waldo in south Arkansas, and the MDF plant is located near El Dorado, Arkansas. In addition to its timber, lumber, and MDF operations, the Company is engaged in real estate development in central Arkansas.
Business Environment	Business Environment — The Company is primarily a wood products producer operating in a commodity-based business environment with a major diversification in real estate development. This environment is affected by a number of factors including general economic conditions, interest rates, credit availability, building product imports, foreign exchange rates, housing starts, new and existing housing inventory, foreclosures, residential repair and remodeling, commercial construction and repair, industry capacity and production levels, the availability of contractors for logging, hauling, and shipping, the availability of raw materials, natural gas pricing, costs of fuel, and weather conditions.
Principles of Consolidation	Principles of Consolidation — The consolidated financial statements of Deltic Timber Corporation include the accounts of Deltic, all majority-owned subsidiaries, and any variable interest entities of which it is the primary beneficiary. Equity investments and joint ventures are accounted for under the equity method if it is determined that the Company does not have control of the entity. Significant intercompany transactions and accounts have been eliminated.
Business Combination	Business Combinations — The Company accounts for business combinations using the acquisition method. The assets acquired and liabilities assumed are measured at fair value on the acquisition date using appropriate valuation methods. The operations of the acquisitions are included in the consolidated financial statements from the date of acquisition. (For additional information, see Note 4 – Business Combinations.)
Use of Estimates	Use of Estimates — In the preparation of the Company’s financial statements in conformity with accounting principles generally accepted in the United States of America, management has made a number of estimates and assumptions related to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities. Actual results may differ from those estimates.
Cash Equivalents	Cash Equivalents — Cash equivalents include investments that have a maturity of three months or less from the date of purchase.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts — The Company records trade accounts receivable at net realizable value. This value includes an appropriate allowance for estimated uncollectible accounts to reflect any loss anticipated on the trade accounts receivable balances and is charged to the provision for doubtful accounts. The allowance is based upon review of specific receivables outstanding and considers factors such as current overall economic conditions, industry-specific economic conditions, historical customer performance, and anticipated customer performance. In the consolidated statements of income, bad debt expense is included in cost of sales. Provisions for bad debt expense were $150,000, $158,000, and $133,000 in 2014, 2013, and 2012, respectively. Charges to the allowance for write-downs were $188,000, $137,000, and $72,000 in 2014, 2013, and 2012, respectively. At December 31, 2014 and 2013, the balance in the allowance account was $123,000 and $172,000, respectively.
Inventories	Inventories — Inventories of logs, wood fiber, lumber, MDF, and supplies are stated at the lower of cost or market within Deltic’s operating areas, primarily using the average cost method. Log costs include harvest and transportation costs as appropriate. Lumber and MDF costs include materials, labor, and production overhead. (For additional information, see Note 2 – Inventories.)
Investment in Del-Tin Fiber	Investment in Del-Tin Fiber — On April 1, 2013, the Company acquired the remaining 50 percent membership interest of Del-Tin Fiber, which had been accounted for as an equity method investment and is now included as a wholly-owned consolidated subsidiary. (For additional information, see Note 4 – Business Combinations.)
Investment in Real Estate Held for Development and Sale	Investment in Real Estate Held for Development and Sale — Real estate held for development and sale includes direct costs of land and land development and indirect costs, including amenities. Indirect and amenity costs are allocated to individual lots or acreage sold based on relative retail sales values. Direct costs are allocated to a specific neighborhood or commercial real estate tract, while indirect costs for the Company’s four developments – Chenal Valley, Wildwood Place, Chenal Downs, and Red Oak Ridge – are allocated to neighborhoods over the entire respective development area based on relative retail sales values.
Timber and Timberlands	Timber and Timberlands — Timber and timberlands, which include timberland, fee timber, purchased stumpage inventory, and logging facilities, are stated at cost, less the cost of fee timber harvested and accumulated depreciation of logging facilities, and include no estimated future reforestation costs. The cost of timber consists of fee timber acquired and reforestation costs, which include site preparation, seedlings, and labor. The cost of fee timber harvested is based on the volume of timber harvested in relation to the estimated volume of timber recoverable. Logging facilities, which consist primarily of roads constructed and other land improvements, are depreciated using the straight-line method over a ten-year estimated life. The Company estimates its fee timber inventory using statistical information and data obtained from physical measurements and other information gathering techniques. Fee timber carrying costs, commercial thinning, silviculture, and timberland management costs are expensed as incurred.
	The Company classifies its timberlands and fee timber as either strategic or non-strategic. Strategic timberlands, including pine forest and pine plantations, are prime pine sawtimber-growing platforms located within or immediately adjacent to the Company sawmills’ operating regions. Deltic manages these acres using modern silviculture methods to achieve optimal volume and quality of its pine sawtimber. The Company harvests pine sawtimber and pine pulpwood in accordance with its harvest plans and generally converts pine sawtimber into lumber in its own sawmills and sells pine pulpwood, hardwood pulpwood, and hardwood sawtimber in the market. Upon harvest, strategic timberlands are reforested. The Company’s timberland acquisition program is focused on the acquisition of pine-growing timberland in its current operating regions. This investment in strategic fee timber is a “productive asset,” and any occasional sale of strategic timberland or any expenditure to acquire such timber and timberlands is included in and classified as an investing activity in the Company’s consolidated statements of cash flows. The Company has legacy hardwood and other acreage which cannot be harvested for conversion in Company sawmills, reforested as pine plantations, or managed efficiently using modern silviculture methods either due to the size of the tract or lack of proximity to other Deltic fee timberlands. These timberlands have been identified as non-strategic and/or higher and better use timberlands and are expected to be sold over time. The Company considers these sales to be an operating activity of its Woodlands segment.
	In order to acquire and sell assets, primarily timberlands, in a tax efficient manner, the Company enters into tax-deferred, like-kind exchange (“LKE”) transactions when possible. The Company generally enters into forward transactions, in which property is sold and the proceeds are reinvested by acquiring similar property, and reverse transactions, in which property is acquired and similar property is subsequently sold. A qualified LKE intermediary is used to facilitate LKE transactions. Proceeds from forward LKE transactions are held by the intermediary and are classified as restricted cash, because the funds must be reinvested in similar properties. If the acquisition of suitable LKE properties is not completed within 180 days of the sale of the Company-owned property, the proceeds are distributed to Deltic by the intermediary and are reclassified as available cash, and applicable income taxes are determined. Amounts deposited with a third party towards the potential future purchase of property are included in deferred charges and other assets in the consolidated balance sheets and as an investing activity as changes in funds held by trustee in the consolidated statements of cash flows. The Company had no proceeds from land sales deposited with an LKE intermediary at December 31, 2014 or 2013. An exchange accommodation titleholder, a type of variable interest entity, is used to facilitate reverse like-kind exchanges. The acquired assets are held by the exchange accommodation titleholder until the exchange transactions are complete. If the Company determines that it is the primary beneficiary of the exchange accommodation titleholder, Deltic includes the assets held by the exchange accommodation titleholder in timber and timberlands assets on the consolidated balance sheets and recognizes any income or expense attributed to the property in the consolidated income statements.
Property, Plant, and Equipment	Property, Plant, and Equipment — Property, plant, and equipment assets are stated at cost less accumulated depreciation. Depreciation of buildings, equipment, and other depreciable assets is calculated primarily using the straight-line method. Expenditures that substantially improve and/or increase the useful life of facilities or equipment are capitalized. Maintenance and repair costs are expensed as incurred. Gains and losses on disposals or retirements are recognized in the period they occur.
	Property, plant, and equipment assets are evaluated for possible impairment on a specific asset basis or in groups of similar assets, as applicable, whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future net cash flows to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment loss is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell, and depreciation ceases.
Revenue Recognition	Revenue Recognition — The Company recognizes revenue when the following criteria are met: (1) persuasive evidence of an agreement exists, (2) delivery has occurred or services have been rendered, (3) the price to the buyer is fixed and determinable, and (4) collectability is reasonably assured. Delivery is not considered to have occurred until the customer takes title and assumes the risks and rewards of ownership. Revenue from the sale of lumber, MDF, and wood by-products is recorded at the time of shipment due to terms of such sale being designated free on board (“f.o.b.”) shipping point. Revenue from consignment sales is recorded when the customer assumes ownership of the product. Revenue from the sale of timber-cutting rights to third parties is recorded when legal title passes to the purchaser, which is generally upon delivery of a legally executed timber deed and receipt of payment for the timber. Revenue from intersegment timber sales is recorded when the timber is harvested; such intersegment sales, which are made at prices which generally approximate market within Deltic’s operating area, are eliminated in the consolidated financial statements.
	Revenue from the leasing of land for hunting purposes is deferred when received and subsequently recognized over the one-year lease term, which begins September 1 of each year. At December 31, 2014 and 2013, the Company had deferred hunting lease revenue totaling $2,009,000 and $1,684,000, respectively, reflected in the consolidated balance sheets in deferred revenues and other accrued liabilities. Revenue from mineral lease rental payments is deferred when received and recognized ratably over the lease term. At December 31, 2014 and 2013, the Company had deferred mineral lease revenue of $1,140,000 and $2,085,000, respectively, of which $383,000 and $649,000 were included in other noncurrent liabilities for 2014 and 2013, respectively, and $757,000 and $1,436,000 were included in other current liabilities, respectively. Mineral royalty payments are recognized when received. Revenue from sales of timberland and real estate is recorded when the sale is closed and legal title is transferred and the buyer’s initial and continuing investment is adequate, which is generally at the time the purchaser executes the real estate closing documents and makes payment to the title company handling the closing.
Income Taxes	Income Taxes — The Company uses the asset and liability method of accounting for income taxes. Under this method, the provision for income taxes includes amounts currently payable and amounts deferred as tax assets and liabilities, based on differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities, and is measured using the enacted tax rates that are expected to be in effect when the differences reverse. Deferred tax assets are reduced by a valuation allowance, which is established when it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized. The effect on deferred tax assets and liabilities of a change in tax law is recognized in income in the period that includes the enactment date. The Company continuously reviews state and federal tax returns for uncertain tax provisions. Liabilities for uncertain tax positions are recorded if it is deemed more-likely-than-not that the positions will be sustained upon examination by the taxing authorities. These liabilities are adjusted in the period in which it is determined that the issue is settled with the relevant taxing authority, or there has been an expiration of statute of limitation for a tax year in question, or a change in tax laws, or other facts become known.
Property Taxes	Property Taxes — Property taxes applicable to the Company’s assets are estimated and accrued in the period of assessment. At December 31, 2014 and 2013, the Company had accrued property tax expense totaling $1,894,000 and $1,798,000, respectively, reflected in the consolidated balance sheets in accrued taxes other than income taxes.
Share-Based Compensation	Share-Based Compensation — The Company applies a fair value-based measurement method in accounting for share-based payment transactions with employees, recognizing the cost as the services are performed. (For additional information, see Note 17 – Incentive Plans.)
Pensions and Other Postretirement Benefits	Pensions and Other Postretirement Benefits — The Company sponsors both qualified and nonqualified, noncontributory, defined benefit retirement plans that cover all eligible employees, excluding employees of the subsidiaries. Benefits are based on years of service and final career-average-pay formulas as defined by the plans. The qualified plan is funded to accumulate sufficient assets to provide for accrued benefits. The nonqualified plan, a supplemental executive plan, is not funded; payments to retirees due under this plan are made on a monthly basis.
	The Company also sponsors a defined benefit health care plan and a life insurance benefit plan for all eligible retired employees, excluding employees of the subsidiaries. The Company measures the costs of its obligations for these plans based on its health care cost trends and actuarial assumptions, including discount rates, mortality rates, assumed rates of return, compensation increases, and turnover rates. The Company reviews its assumptions on an annual basis and makes modifications to the assumptions based on current rates and trends when it is appropriate to do so. The effect of modifications to those assumptions is recorded in accumulated other comprehensive income/(loss) and amortized to net periodic cost over future periods using the corridor method. The Company believes that the assumptions utilized in recording its obligations under its plans are reasonable based on its experience and market conditions.
	Net periodic costs are recognized as employees render the services necessary to earn these post- retirement benefits. (For additional information, see Note 16 – Employee and Retiree Benefit Plans.)
Advertising Costs	Advertising Costs — Advertising costs, primarily related to marketing efforts for the Company’s real estate developments, are expensed as incurred. These costs amounted to $764,000 in 2014, $716,000 in 2013, and $732,000 in 2012, and are reflected in the consolidated statements of income.
Capitalized Interest	Capitalized Interest — The Company capitalizes interest for qualifying assets during construction by applying the Company’s capitalization rate to the average amount of accumulated expenditures for the asset during the period. Interest is most often capitalized as an indirect cost for real estate development in the Company’s real estate operations. (For additional information, see Note 18 – Supplemental Cash Flows Disclosures.)
Timberland Acquisition Expenditures	Timberland Acquisition Expenditures — These expenditures are the costs incurred to purchase timber and timberland, and the costs which are allocated to timber, reforestation, or land are based on various factors such as age and number of trees on the acreage acquired. These expenditures are classified as investing activities in the Company’s consolidated statements of cash flows.
Capital Expenditures	Capital Expenditures — Capital expenditures include additions to investment in real estate held for development and sale; capitalized reforestation costs and logging facilities of timber and timberlands; and property, plant, and equipment.
Net Change in Purchased Stumpage Inventory	Net Change in Purchased Stumpage Inventory — Purchased stumpage inventory consists of timber-cutting rights purchased from third parties specifically for use in the Company’s sawmills. Depending on the timing of acquisition and usage of this acquired stumpage inventory, the net change in this inventory can either be a source or use of cash in the Company’s consolidated statements of cash flows.
Earnings per Common Share	Earnings per Common Share — Basic earnings per share is computed using the two-class method and is based on earnings available to common shareholders less accrued preferred dividends, if any, and the weighted average number of common shares outstanding. The diluted earnings per share amounts are computed based on earnings available to common shareholders and the weighted average number of common shares outstanding, including shares assumed to be issued under the Company’s stock incentive plans using the treasury-stock method, unless anti-dilutive. (For a reconciliation of amounts used in per share computations, see Note 19 – Earnings per Share.)
Shipping and Handling Costs	Shipping and Handling Costs — Shipping and handling costs, such as freight to the customers’ destinations, are included in cost of sales in the Company’s consolidated statements of income. These costs, when included in the amount invoiced to customers, are also recognized in net sales.
Off-Balance Sheet Arrangements	Off-Balance Sheet Arrangements — The Company evaluates its transactions to determine if any variable interest entities exist. If it is determined that Deltic is the primary beneficiary of a variable interest entity, that entity is consolidated into Deltic’s financial statements.
Effect of Recently Issued Authoritative Accounting Guidance	Effect of Recently Issued Authoritative Accounting Guidance — Financial Accounting Standards Update (“ASU”) No. 2014-09, “Revenue from Contracts with Customers,” requires an entity to recognize the amount of revenue it expects to be entitled to for the transfer of promised goods or services to customers. This ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for the Company on January 1, 2017, and early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company continues to evaluate the standard and has not yet selected a transition method but believes the standard will have little impact on its consolidated financial statements and disclosures.

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventories	Inventories at December 31 consisted of the following:
	(Thousands of dollars)	2014		2013
	Raw materials   - Logs	$	772		1,612
	- Del-Tin – wood fiber		384		440
	Finished goods  - Lumber		4,168		4,145
	- Medium density fiberboard (“MDF”)		3,889		3,110
	- MDF consigned to others		926		708
	Supplies		1,355		2,424
		$	11,494		12,439

Prepaid_Expenses_and_Other_Cur1

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets at December 31 consisted of the following:
	(Thousands of dollars)	2014		2013
	Short-term deferred tax assets	$	2,087		1,901
	Refundable income taxes		2,537		109
	Prepaid expenses		654		692
	Other current assets		686		453
		$	5,964		3,155

Business_Combinations_Tables

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Purchase Price Allocated to Net Tangible and Intangible Assets	The purchase price allocated to the net tangible and intangible assets acquired and liabilities assumed based on their fair values as of the acquisition date and the calculation of the gain on bargain purchase were as follows:
	(Thousands of dollars)
	Accounts receivable		$	4,229
	Inventories			4,805
	Other current assets			360
	Property, plant, and equipment			40,960
	Intangible assets1			1,700
	Other assets			171
	Current liabilities			(1,653	)
	Deferred tax liabilities			(2,203	)
	Long-term liabilities			(29,000	)
	Net assets acquired			19,369
	Cash paid			(5,170	)
	Fair value of previously held investment in Del-Tin Fiber			(10,786	)
	Gain on bargain purchase		$	3,413
		1	The acquired intangible assets consist of internally developed software which is being amortized over three years.
Summarizes Combined Results of Operations on Pro Forma Basis	This information is based on historical results of operations, adjusted for certain acquisition accounting adjustments, and does not purport to represent Deltic’s actual results of operations as if the acquisition transaction described above would have occurred as of January 1, 2012, nor is it necessarily indicative of future results.
			Twelve Months Ended
			December 31,
	(Thousands of dollars, except per share amounts)		2013			2012
	Net sales		$	217,268		$	207,446
	Net income			21,193			8,846
	Basic earnings per common share			1.69			0.71
	Diluted earnings per common share			1.68			0.7

Timber_and_Timberlands_Tables

Timber and Timberlands (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Summary of Timber and Timberlands	Timber and timberlands at December 31 consisted of the following:
	(Thousands of dollars)	2014			2013
	Purchased stumpage inventory	$	1,620			2,388
	Timberlands		155,704			102,609
	Fee timber		322,714			253,768
	Logging facilities		2,720			2,628
			482,758			361,393
	Less accumulated cost of fee timber harvested and facilities depreciation		(118,670	)		(113,056	)
	Strategic timber and timberlands		364,088			248,337
	Non-strategic timber and timberlands		322			496
		$	364,410			248,833

Property_Plant_and_Equipment_T

Property, Plant, and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	Property, plant, and equipment at December 31 consisted of the following:
	(Thousands of dollars)	Range of	2014			2013
		Useful Lives
	Land	N/A	$	947			947
	Land improvements	10-20 years		8,163			8,835
	Buildings and structures	10-20 years		22,680			22,599
	Machinery and equipment	3-15 years		152,641			145,741
				184,431			178,122
	Less accumulated depreciation			(110,267	)		(102,863	)
			$	74,164			75,259

Deferred_Revenues_and_Other_Ac1

Deferred Revenues and Other Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Deferred Revenues and Other Accrued Liabilities	Deferred revenues and other accrued liabilities at December 31 consisted of the following:
	(Thousands of dollars)	2014		2013
	Deferred revenues – current	$	3,310		3,697
	Vacation accrual		1,312		1,290
	Deferred compensation		1,166		3,442
	All other current liabilities		1,435		1,901
		$	7,223		10,330

Other_Noncurrent_Liabilities_T

Other Noncurrent Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Other Noncurrent Liabilities	Other noncurrent liabilities at December 31 consisted of the following:
	(Thousands of dollars)	2014		2013
	Accumulated postretirement benefit obligation	$	12,343		10,391
	Excess retirement plan		9,372		4,457
	Accrued pension liability		14,955		6,383
	Deferred revenue – long-term portion		383		649
	Uncertain tax positions liability		—		1,185
	All other noncurrent payables		2,287		2,678
		$	39,340		25,743

Indebtedness_Tables

Indebtedness (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Company's Indebtedness	The Company’s indebtedness at December 31 consisted of the following:
	(Thousands of dollars)		2014			2013
	Notes payable, 1.67%¹, due 2019 (See Note 9 – Credit Facilities)		$	134,000			21,000
	Senior notes payable, 6.10%, due 2016			40,000			40,000
	Union County, Arkansas Taxable Industrial Revenue Bonds, .29%², due 2027			29,000			29,000
	Long-term debt		$	203,000			90,000
		¹	Weighted average interest rate for Notes payable at December 31, 2014 and 2013 was 1.67% and 1.54%, respectively.
		²	Weighted average interest rate for Bonds at December 31, 2014 and 2013 was .29% and .31%, respectively.
Ratio Requirements for Revolving Credit Facility and Senior Notes Payable	The table below sets forth the ratio requirements of the covenants in both the revolving credit facility and Senior Notes Payable and the status with respect to these covenants as of December 31, 2014 and 2013.
			Covenants			Actual Ratios at			Actual Ratios at
			Requirements			Dec. 31, 2014			Dec. 31, 2013
	Leverage ratio should be less than:1			.65 to 1			.432 to 1			.254 to 1
	Total outstanding debt as a percentage of total debt allowed based on the minimum timber market value covenant:2			—	2		74.94	%		48.24	%
	1	The leverage ratio is calculated as total debt divided by total capital. Total debt includes indebtedness for borrowed money, secured liabilities, obligations in respect of letters of credit, and guarantees. Total capital is the sum of total debt and net worth. Net worth is calculated as total assets minus total liabilities, as reflected on the balance sheet. This covenant is applied at the end of each quarter.
	2	Timber market value must be greater than 175 percent of total debt (as defined in (1) above). The timber market value is calculated by multiplying the average price received for sales of timber for the preceding four quarters by the current quarter’s ending inventory of timber. This covenant is applied at the end of the quarter on a rolling four-quarter basis.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense/(Benefit)	The components of income tax expense/(benefit) related to income from operations for the years ended December 31, 2014, 2013, and 2012 are as follows:
	(Thousands of dollars)	2014			2013			2012
	Federal
	Current	$	9,959			10,237			4,743
	Deferred		(961	)		138			(685	)
			8,998			10,375			4,058
	State
	Current		887			2,154			707
	Deferred		(292	)		103			36
			595			2,257			743
	Total income tax expense	$	9,593			12,632			4,801
Schedule of Reconciliation of Income Tax Expense	The following table provides a reconciliation of the Company’s income tax expense at the statutory U.S. federal rate of 35 percent to the actual income tax expense for the years ended December 31, 2014, 2013, and 2012.
	(Thousands of dollars)	2014			2013			2012
	U.S. federal income tax using statutory tax rate	$	10,239			13,588			4,913
	State tax, net of federal tax benefit		1,130			1,458			446
	Permanent differences		(1,000	)		(1,219	)		(558	)
	Tax effects resulting from:
	Gain on bargain purchase		—			(1,195	)		—
	Reversal of uncertain state income tax position		(776	)		—			—
	Income tax provision as reported	$	9,593			12,632			4,801
Schedule of Deferred Tax Assets and Deferred Tax Liabilities	The Company’s deferred tax assets and deferred tax liabilities at December 31, 2014 and 2013 consisted of the following:
	(Thousands of dollars)	2014			2013
	Deferred tax assets
	Investment in real estate held for development and sale	$	17,286			16,914
	Postretirement and other employee benefits		20,086			13,435
	Other deferred tax assets		2,093			2,360
	Total deferred tax assets		39,465			32,709
	Deferred tax liabilities
	Timber and timberlands		(27,191	)		(26,158	)
	Property, plant, and equipment		(11,021	)		(11,838	)
	Other deferred tax liabilities		(268	)		(326	)
	Total deferred tax liabilities		(38,480	)		(38,322	)
	Net deferred tax assets/(liabilities)	$	985			(5,613	)
Schedule of Deferred Tax Assets and Liabilities Classified in Accompanying Consolidated Balance Sheets	The deferred tax assets and liabilities are classified in the accompanying consolidated balance sheets as follows:
	(Thousands of dollars)	2014			2013
	Current tax assets	$	2,087			1,901
	Long-term tax liabilities		(1,102	)		(7,514	)
	Net deferred tax assets/(liabilities)	$	985			(5,613	)
Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits (excluding both interest and any related federal benefits) is as follows:
	(Thousands of dollars)	2014			2013
	Balance at January 1	$	1,185			1,331
	Lapse of statute		(1,185	)		(146	)
	Balance at December 31	$	—			1,185

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements for Financial Liabilities Accounted on a Recurring Basis	The fair value measurements for the Company’s financial liabilities accounted for at fair value on a recurring basis at December 31, 2014 are presented in the following table:
				Fair Value Measurements at Reporting Date Using
		December 31,		Quoted Prices in		Significant		Significant
				Active Markets for		Observable		Unobservable
				Identical		Inputs		Inputs
				Liabilities Inputs
	(Thousands of dollars)	2014		Level 1		Level 2		Level 3
	Liabilities
	Nonqualified employee savings plan	$	1,504		1,504		—		—
Carrying Amounts and Estimated Fair Values of Financial Instruments	The following table presents the carrying amounts and estimated fair values of financial instruments held by the Company at December 31, 2014 and 2013. The fair value of a financial instrument is the amount at which the instrument could be exchanged in a current transaction between willing parties. The table excludes financial instruments included in current assets and liabilities, except current maturities of long-term debt, all of which have fair values approximating carrying values.
		2014				2013
	(Thousands of dollars)	Carrying		Estimated		Carrying		Estimated
		Amount		Fair Value		Amount		Fair Value
	Financial liabilities
	Long-term debt, including current maturities	$	203,000		207,077		90,000		94,534

Other_Comprehensive_Income_Dis1

Other Comprehensive Income Disclosures (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Changes in Accumulated Other Comprehensive Loss by Component (Net of Tax)	Changes in Accumulated Other Comprehensive Loss by Component (Net of Tax)
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	AOCL at January 1, 2014	$	(2,410	)		(482	)		213			(2,679	)
	Amounts reclassified from AOCL		111			173			(121	)		163
	Net loss arising during period		(5,316	)		(2,755	)		(824	)		(8,895	)
	Net current period other comprehensive loss		(5,205	)		(2,582	)		(945	)		(8,732	)
	AOCL at December 31, 2014	$	(7,615	)		(3,064	)		(732	)		(11,411	)
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	AOCL at January 1, 2013	$	(9,553	)		(3,380	)		(1,170	)		(14,103	)
	Amounts reclassified from AOCL		529			38			(116	)		451
	Net gain arising during period		6,614			2,860			1,499			10,973
	Net current period other comprehensive income		7,143			2,898			1,383			11,424
	AOCL at December 31, 2013	$	(2,410	)		(482	)		213			(2,679	)
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	AOCL at January 1, 2012	$	(8,124	)		(855	)		(750	)		(9,729	)
	Amounts reclassified from AOCL		608			226			(77	)		757
	Net loss arising during period		(2,037	)		(2,751	)		(343	)		(5,131	)
	Net current period other comprehensive loss		(1,429	)		(2,525	)		(420	)		(4,374	)
	AOCL at December 31, 2012	$	(9,553	)		(3,380	)		(1,170	)		(14,103	)
Reclassification Out of Accumulated Other Comprehensive Loss	Reclassification Out of Accumulated Other Comprehensive Loss
	Details about AOCL Components
		For the Year Ended December 31, 2014
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	Amortization of prior service costs	$	17			(7	)		—			10
	Amortization of actuarial losses		165			292			—			457
	Amortization of plan amendment		—			—			(199	)		(199	)
	Total before tax		182			285			(199	)		268
	Income tax benefit/(expense)		(71	)		(112	)		78			(105	)
	Total reclassifications – net of tax	$	111			173			(121	)		163
		For the Year Ended December 31, 2013
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	Amortization of prior service costs	$	18			(11	)		—			7
	Amortization of actuarial losses		852			74			8			934
	Amortization of plan amendment		—			—			(199	)		(199	)
	Total before tax		870			63			(191	)		742
	Income tax benefit/(expense)		(341	)		(25	)		75			(291	)
	Total reclassifications – net of tax	$	529			38			(116	)		451
	Amounts in parentheses indicate expenses. These items are included in the computation of net periodic retirement and postretirement costs. See Note 16 – Employee and Retiree Benefit Plans.
		For the Year Ended December 31, 2012
	(Thousands of dollars)	Defined			Defined			Post-			Total
		Benefit			Benefit			Retirement
		Funded			Unfunded			Benefit
		Retirement			Retirement			Plan
		Plan			Plan
	Amortization of prior service costs	$	18			(11	)		—			7
	Amortization of actuarial losses		982			383			73			1,438
	Amortization of plan amendment		—			—			(199	)		(199	)
	Total before tax		1,000			372			(126	)		1,246
	Income tax benefit/(expense)		(392	)		(146	)		49			(489	)
	Total reclassifications – net of tax	$	608			226			(77	)		757
	Amounts in parentheses indicate expenses. These items are included in the computation of net periodic retirement and postretirement costs. See Note 16 – Employee and Retiree Benefit Plans.
Tax Effects by Component	Tax Effects by Component
		For the Year Ended December 31, 2014
	(Thousands of dollars)	Before			Tax			Net of
		Tax			(Expense)			Tax
		Amount			or Benefit			Amount
	Gains/(losses) arising during the period	$	(14,636	)		5,741			(8,895	)
	Amortization of prior service costs		10			(4	)		6
	Amortization of actuarial losses/(gains)		457			(179	)		278
	Amortization of plan amendment		(199	)		78			(121	)
		$	(14,368	)		5,636			(8,732	)
		For the Year Ended December 31, 2013
	(Thousands of dollars)	Before			Tax			Net of
		Tax			(Expense)			Tax
		Amount			or Benefit			Amount
	Gains/(losses) arising during the period	$	18,054			(7,081	)		10,973
	Amortization of prior service costs		7			(3	)		4
	Amortization of actuarial losses/(gains)		934			(366	)		568
	Amortization of plan amendment		(199	)		78			(121	)
		$	18,796			(7,372	)		11,424
		For the Year Ended December 31, 2012
	(Thousands of dollars)	Before			Tax			Net of
		Tax			(Expense)			Tax
		Amount			or Benefit			Amount
	Gains/(losses) arising during the period	$	(8,442	)		3,311			(5,131	)
	Amortization of prior service costs		7			(3	)		4
	Amortization of actuarial losses/(gains)		1,438			(564	)		874
	Amortization of plan amendment		(199	)		78			(121	)
		$	(7,196	)		2,822			(4,374	)

Employee_and_Retiree_Benefit_P1

Employee and Retiree Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Plan Benefit Obligations, Fair Value of Plan Assets, and Funded Status	The following table sets forth the plans’ benefit obligations, fair value of plan assets, and funded status at December 31, 2014 and 2013.
		Defined Benefit						Defined Benefit						Other
		Funded						Unfunded						Postretirement
		Retirement						Retirement						Benefit
		Plan						Plan						Plan
	(Thousands of dollars)	2014			2013			2014			2013			2014			2013
	Change in benefit obligation
	Benefit obligation at beginning of period	$	37,010			42,716			4,690			9,299			10,756			12,542
	Service cost		1,476			1,549			302			143			418			450
	Interest cost		1,839			1,557			373			192			497			431
	Participant contributions		—			—			—			—			88			88
	Actuarial (gain)/loss		8,626			(7,672	)		4,534			(4,705	)		1,355			(2,466	)
	Benefits paid		(1,201	)		(1,140	)		(255	)		(239	)		(416	)		(289	)
	Benefit obligation at end of period	$	47,750			37,010			9,644			4,690			12,698			10,756
	Change in plan assets
	Fair value of plan assets at beginning of period	$	30,627			25,463			—			—			—			—
	Actual return on plan assets		2,327			5,237			—			—			—			—
	Employer contributions		1,200			1,200			255			239			328			201
	Participant contributions		—			—			—			—			88			88
	Benefits paid		(1,201	)		(1,140	)		(255	)		(239	)		(416	)		(289	)
	Expenses		(158	)		(133	)		—			—			—			—
	Fair value of plan assets at end of period	$	32,795			30,627			—			—			—			—
	Funded status of plans	$	(14,955	)		(6,383	)		(9,644	)		(4,690	)		(12,698	)		(10,756	)
	Amounts recognized in the balance sheet
	Current liability	$	—			—			(272	)		(233	)		(355	)		(365	)
	Noncurrent liability	$	(14,955	)		(6,383	)		(9,372	)		(4,457	)		(12,343	)		(10,391	)
	Deferred income taxes – net	$	5,866			2,504			3,783			1,840			4,981			4,219
	Accumulated other comprehensive (income)/loss	$	7,615			2,410			3,064			482			732			(213	)
	Amounts recognized in accumulated other comprehensive loss
	Net unrecognized (gain)/loss	$	12,525			3,942			5,041			799			1,231			(124	)
	Unrecognized prior service cost/(credit)		4			21			—			(7	)		(46	)		(245	)
	Tax effects		(4,914	)		(1,553	)		(1,977	)		(310	)		(453	)		156
		$	7,615			2,410			3,064			482			732			(213	)
		Defined Benefit						Defined Benefit						Other
		Funded						Unfunded						Postretirement
		Retirement						Retirement						Benefit
		Plan						Plan						Plan
	(Thousands of dollars)	2014			2013			2014			2013			2014			2013
	Assumptions used in measurement of benefit obligations
	Weighted average discount rate		4.21	%		4.84	%		4.21	%		4.84	%		4.25	%		4.85	%
	Rate of compensation increase		4	%		4	%		4	%		4	%		N/A			N/A
	Accumulated benefit obligations at year end	$	40,720			32,272			6,792			4,660			N/A			N/A
Retirement Expense and Other Postretirement Benefits Expense	Components of net periodic retirement expense and other postretirement benefits expense consisted of the following:
	(Thousands of dollars)	2014			2013			2012
	Defined benefit funded retirement plan
	Service cost	$	1,476			1,549			1,630
	Interest cost		1,839			1,557			1,622
	Expected return on plan assets		(2,290	)		(1,894	)		(1,692	)
	Amortization of prior service cost		17			18			18
	Amortization of actuarial loss		165			852			982
	Net periodic benefit cost	$	1,207			2,082			2,560
	Defined benefit unfunded retirement plan
	Service cost	$	302			143			364
	Interest cost		373			193			355
	Amortization of prior service credit		(7	)		(11	)		(11	)
	Amortization of actuarial loss		292			74			383
	Net periodic benefit cost	$	960			399			1,091
	Other postretirement benefit plan
	Service cost	$	418			450			455
	Interest cost		497			431			467
	Amortization of prior service credit		(199	)		(199	)		(199	)
	Amortization of actuarial loss		—			8			73
	Net periodic benefit cost	$	716			690			796
Assumptions Used to Determine Net Periodic Benefit Cost - Pension Plans
	(Thousands of dollars)	2014			2013			2012
	Assumptions used to determine net periodic benefit cost – defined benefit pension plans
	Weighted average discount rate		4.84	%		3.94	%		4.34	%
	Expected long-term rate of return on plan assets		7.5	%		7.5	%		7.5	%
	Rate of compensation increase		4	%		4	%		4	%
	Assumptions used to determine net periodic benefit cost – other postretirement plan
	Weighted average discount rate		4.85	%		3.9	%		4.3	%
	Other changes in plan assets and benefit obligations recognized in other comprehensive (income)/loss
	Net unrecognized loss/(gain)	$	14,636			(18,054	)		8,442
	Amortization of prior service credit		(10	)		(7	)		(7	)
	Amortization of actuarial losses		(457	)		(934	)		(1,438	)
	Amortization of plan amendment		199			199			199
	Tax effect of changes		(5,636	)		7,372			(2,822	)
	Total recognized in other comprehensive (income)/loss	$	8,732			(11,424	)		4,374
Estimated Benefit Payments by Year
	(Thousands of dollars)	Defined			Defined			Other
		Benefit			Benefit			Post-
		Funded			Unfunded			Retirement
		Retirement			Retirement			Benefit
		Plan			Plan			Plan
	Estimated benefit payments by year
	2015	$	1,351			272			355
	2016		1,421			270			369
	2017		1,535			267			405
	2018		1,668			264			447
	2019		1,835			261			498
	2020 - 2024		12,359			2,849			3,180
Fair Value Investments Plan	The following table sets forth by level within the fair value hierarchy the Plan’s investments at fair value as of December 31, 2014.
		Fair Value Measurements at Reporting Date Using
	(Thousands of dollars)	Percent			Total			Level 1			Level 2			Level 3
		of			Carrying
		Total			Value at
					Dec. 31,
					2014
	Plan Investments
	Cash and cash equivalents		4.5		$	1,470			1,470			—			—
	Other		0.1			40			40			—			—
	Equity securities by sector:
	Energy		0.3			105			105			—			—
	Materials and industrials		2			652			652			—			—
	Consumer		3.9			1,274			1,274			—			—
	Health care		2.6			854			854			—			—
	Financials		0.6			201			201			—			—
	Information tech		4.6			1,503			1,503			—			—
	Foreign stocks		1			319			319			—			—
	U.S. Govt. and agency securities		15.2			5,001			3,208			1,793			—
	Corporate debt obligations		7.2			2,370			—			2,370			—
	Mutual funds:
	Dividends and growth		28.4			9,327			9,327			—			—
	International and emerging markets		5.6			1,835			1,835			—			—
	Fixed income		2.3			742			742			—			—
	Exchange-traded funds		15			4,913			4,913			—			—
	Alternative investment funds		6.7			2,189			—			—			2,189
	Total plan investments at fair value		100		$	32,795			26,443			4,163			2,189
	Percent of fair value hierarchy					100			80.6			12.7			6.7
	The following table sets forth by level within the fair value hierarchy the Plan’s investments at fair value as of December 31, 2013.
		Fair Value Measurements at Reporting Date Using
	(Thousands of dollars)	Percent			Total			Level 1			Level 2			Level 3
		of			Carrying
		Total			Value at
					Dec. 31,
					2013
	Plan Investments
	Cash and cash equivalents		3.2		$	984			984			—			—
	Other		0.2			54			54			—			—
	Equity securities by sector:
	Energy		0.4			111			111			—			—
	Materials and industrials		2.6			784			784			—			—
	Consumer		4.7			1,435			1,435			—			—
	Health care		2.5			771			771			—			—
	Financials		0.8			259			259			—			—
	Information tech		4.6			1,409			1,409			—			—
	Foreign stocks		1			302			302			—			—
	U.S. Govt. and agency securities		12.3			3,775			1,633			2,142			—
	Corporate debt obligations		10.7			3,287			—			3,287			—
	Mutual funds:
	Dividends and growth		29.5			9,042			9,042			—			—
	International and emerging markets		5.9			1,798			1,798			—			—
	Exchange-traded funds		14.8			4,539			4,539			—			—
	Alternative investment funds		6.8			2,077			—			—			2,077
	Total plan investments at fair value		100		$	30,627			23,121			5,429			2,077
	Percent of fair value hierarchy					100			75.5			17.7			6.8
Activity in Level 3 Investments	The following table sets forth the activity in the Level 3 investments for the year ended December 31, 2014.
		Fair Value Measurements
		Using Significant
		Unobservable Inputs
		(Level 3)
	(Thousands of dollars)	Alternative Investment
		Funds
	Beginning balance at December 31, 2013	$	2,077
	Actual return on plan assets:
	Relating to assets still held at the reporting date		112
	Purchases, sales, and settlements		—
	Ending balance at December 31, 2014	$	2,189
	The following table sets forth the activity in the Level 3 investments for the year ended December 31, 2013.
		Fair Value Measurements
		Using Significant
		Unobservable Inputs
		(Level 3)
	(Thousands of dollars)	Alternative Investment
		Funds
	Beginning balance at December 31, 2012	$	—
	Actual return on plan assets:
	Relating to assets still held at the reporting date		77
	Purchases, sales, and settlements		2,000
	Ending balance at December 31, 2013	$	2,077

Incentive_Plans_Tables

Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Valuation of Stock Options and Restricted Stock Performance Units	Assumptions for the 2014, 2013, and 2012 valuation of stock options and restricted stock performance units consisted of the following:
		2014			2013			2012
	Expected term of options (in years)		6.27			6.27			6.27
	Weighted expected volatility		37.38	%		37.78	%		38.78	%
	Dividend yield		0.55	%		0.58	%		0.61	%
	Risk-free interest rate - performance restricted shares		1.23	%		0.6	%		0.6	%
	Risk-free interest rate - stock options		2.99	%		1.98	%		2	%
	Stock price as of valuation date	$	63.21			71.35			67.67
	Restricted performance share valuation	$	80.56			87.74			90.61
	Grant date fair value - stock options	$	21.87			26.2			24.92
Summary of Stock Options	A summary of stock options as of December 31, 2014, and changes during the year ended are presented below:
		Shares			Weighted			Weighted			Aggregate
					Average			Average			Intrinsic
					Exercise			Remaining			Value
					Price			Contractual			$0
								Term (Years)
	Outstanding at January 1, 2014		131,456		$	59.64
	Granted		26,611			63.35
	Exercised		(5,854	)		43.3
	Forfeited/expired		(460	)		36.61
	Outstanding at December 31, 2014		151,753		$	60.99			6.1		$	1,197
	Exercisable at December 31, 2014		87,552		$	56.96			4.6		$	1,020
Summary of Stock Options Outstanding	Additional information about stock options outstanding at December 31, 2014, consisted of the following:
		Options Outstanding									Options Exercisable
	Range of Exercise Prices	Number			Average			Average			Number		Average
		of			Life in			Exercise			of		Exercise
		Options			Years			Price			Options		Price
	$31.00—$35.00		2,766			4.1		$	34.41			2,766	$	34.41
	$41.00—$45.00		14,020			5.1		$	44.84			14,020	$	44.84
	$51.00—$55.00		31,848			1.9		$	53.01			31,848	$	53.01
	$56.00—$65.00		52,462			7.6		$	63.38			19,727	$	63.54
	$66.00—$75.00		50,657			7.6		$	69.45			19,191	$	68.85
			151,753									87,552
Summary of Nonvested Restricted Stock	A summary of nonvested restricted stock as of December 31, 2014, and changes during the year then-ended are presented below:
		Shares			Weighted
					Average
					Grant-Date
					Fair Value
	Nonvested at January 1, 2014		79,591		$	62.31
	Granted		24,951			63.3
	Vested		(19,132	)		44.84
	Nonvested at December 31, 2014		85,410		$	66.51
Summary of Nonvested Restricted Stock Performance Units	A summary of nonvested restricted stock performance units as of December 31, 2014, and changes during the year then-ended are presented below:
		Shares			Weighted
					Average
					Grant-Date
					Fair Value
	Nonvested at January 1, 2014		52,625		$	80.87
	Granted		16,613			80.7
	Units not meeting vesting conditions		(12,652	)		58.66
	Nonvested at December 31, 2014		56,586		$	85.78

Supplemental_Cash_Flows_Disclo1

Supplemental Cash Flows Disclosures (Tables)	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Elements [Abstract]
Interest and Income Taxes Information Concerning Cash Flows	Additional information concerning cash flows at December 31 consisted of the following:
	(Thousands of dollars)	2014			2013			2012
	Income taxes paid in cash	$	14,976			11,042			4,227
	Interest paid		5,420			3,954			3,571
	Interest capitalized		(70	)		(53	)		(36	)
Non-cash Investing and Financing Activities	Non-cash investing and financing activities excluded from the Consolidated Statement of Cash Flows include:
	(Thousands of dollars)	2014			2013			2012
	Issuance of restricted stock	$	1,290			935			1,393
	Capital expenditures accrued, not paid		738			1,271			79
	Fair value of Del-Tin Fiber net assets acquired		—			19,369			—
(Increases)/Decreases in Operating Working Capital, Other Than Cash and Cash Equivalents	(Increases)/decreases in operating working capital, other than cash and cash equivalents, for each of the three years ended December 31 consisted of the following:
	(Thousands of dollars)	2014			2013			2012
	Trade accounts receivable	$	(1,756	)		2,178			(457	)
	Other receivables		8			(6	)		(12	)
	Inventories		945			(2,740	)		(541	)
	Prepaid expenses and other current assets		(2,543	)		(184	)		963
	Trade accounts payable		(2,123	)		3,701			35
	Accrued taxes other than income taxes		(61	)		216			(19	)
	Deferred revenues and other accrued liabilities		(3,644	)		2,718			2,486
		$	(9,174	)		5,883			2,455

Earnings_per_Share_Tables

Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Computation of Earnings Per Share	The amounts used in computing earnings per share and the effect on income and weighted-average number of shares outstanding of dilutive potential common stock consisted of the following at December 31:
	(Thousands of dollars, except per share amounts)	2014		2013		2012
	Net earnings allocated to common stock	$	19,445		25,924		9,144
	Net earnings allocated to participating securities		217		268		91
	Net income allocated to common stock and participating securities	$	19,662		26,192		9,235
	Weighted average number of common shares used in basic EPS		12,497		12,566		12,525
	Effect of dilutive stock awards		56		58		63
	Weighted average number of common shares and dilutive potential common stock used in EPS assuming dilution		12,553		12,624		12,588
	Earnings per common share
	Basic	$	1.56		2.06		0.73
	Assuming dilution	$	1.55		2.05		0.73
Information about Potentially Dilutive Securities Outstanding	The following table provides information about potentially dilutive securities that were outstanding but were not included in the computation of diluted earnings per share because they were anti-dilutive or, in the case of the restricted performance shares, did not meet the metrics established for awarding:
		2014		2013		2012
	Options		76,968		50,197		26,459
	Restricted performance shares		56,586		52,625		29,831

Business_Segments_Tables

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Summary of Company's Business Segments	Information about the Company’s business segments consisted of the following:
	(Thousands of dollars)		2014			2013			2012
	Net sales
	Woodlands		$	37,008			33,834			37,285
	Manufacturing2			189,561			167,955			105,956
	Real Estate			16,283			11,734			10,992
	Eliminations1			(15,497	)		(13,821	)		(13,325	)
			$	227,355			199,702			140,908
	Income before income taxes
	Operating income/(loss)
	Woodlands		$	19,113			16,749			18,374
	Manufacturing2			31,440			38,496			18,083
	Real Estate			1,115			(1,430	)		(2,099	)
	Corporate			(17,405	)		(17,994	)		(17,394	)
	Eliminations			133			(158	)		168
	Operating income			34,396			35,663			17,132
	Equity in earnings of Del-Tin Fiber2			—			1,084			959
	Interest income			5			13			17
	Interest and other debt expense, net of capitalized interest			(5,430	)		(4,578	)		(4,092	)
	Gain on bargain purchase			—			3,413			—
	Other income			284			3,229			20
			$	29,255			38,824			14,036
	Total assets at year-end
	Woodlands		$	363,436			247,156			240,026
	Manufacturing2			80,023			85,837			30,136
	Real Estate			57,646			59,549			58,783
	Corporate3,4			26,164			18,802			24,264
			$	527,269			411,344			353,209
	Depreciation, amortization, and cost of fee timber harvested
	Woodlands		$	5,765			4,785			4,786
	Manufacturing2			12,147			9,910			5,378
	Real Estate			355			343			374
	Corporate			75			93			104
			$	18,342			15,131			10,642
	Capital expenditures5
	Woodlands		$	4,038			3,836			4,026
	Manufacturing2			12,311			16,532			2,478
	Real Estate			3,934			4,267			2,996
	Corporate			49			14			7
			$	20,332			24,649			9,507
	Timberland acquisition expenditures5		$	118,203			8,919			14,527
		1	Primarily intersegment sales of timber from Woodlands to Manufacturing.
		2	Del-Tin Fiber became a consolidated subsidiary, reported in the Manufacturing segment, upon acquisition of a controlling interest of its ownership effective April 1, 2013.
		3	Includes investment in Del-Tin Fiber, an equity method investee, of $6,293,000 at December 31, 2012. (For additional information, see Note 4 – Business Combinations.)
		4	Includes balance of timberland sale proceeds held by trustee, and there were none as of December 31, 2014 and 2013 and $7,000 as of December 31, 2012.
		5	Some 2013 and 2012 amounts have been reclassified to conform to the 2014 presentation.

Financial_Results_by_Quarter_U1

Financial Results by Quarter (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Results
			2014
			First		Second		Third		Fourth		Year
			Quarter		Quarter		Quarter		Quarter
	Net sales		$	55,379		58,605		58,301		55,070		227,355
	Gross profit			13,930		14,455		14,046		10,447		52,878
	Operating income			8,807		9,734		8,782		7,073		34,396
	Net income			4,911		5,298		5,974		3,479		19,662
	Earnings per common share
	Basic		$	0.39		0.42		0.47		0.28		1.56
	Assuming dilution			0.39		0.42		0.47		0.28		1.55
	Dividends paid per common share2		$	0.1		0.1		0.1		0.1		0.4
			2013
			First		Second		Third		Fourth		Year
			Quarter		Quarter		Quarter		Quarter
	Net sales		$	41,563		53,247		56,520		48,372		199,702
	Gross profit			15,384		14,648		14,810		8,977		53,819
	Operating income			10,548		10,991		9,599		4,525		35,663
	Net income1			6,774		11,268		5,813		2,337		26,192
	Earnings per common share
	Basic		$	0.53		0.89		0.46		0.18		2.06
	Assuming dilution			0.53		0.88		0.46		0.18		2.05
	Dividends paid per common share2		$	0.1		0.1		0.1		0.1		0.4
	(Thousands of dollars, except per share amounts)
			2012
			First		Second		Third		Fourth		Year
			Quarter		Quarter		Quarter		Quarter
	Net sales		$	30,639		37,105		36,499		36,665		140,908
	Gross profit			5,730		10,205		10,237		9,388		35,560
	Operating income			1,134		6,259		5,104		4,635		17,132
	Net income			97		3,516		3,218		2,404		9,235
	Earnings per common share
	Basic		$	0.01		0.28		0.25		0.19		0.73
	Assuming dilution			0.01		0.28		0.25		0.19		0.73
	Dividends paid per common share2		$	0.075		0.075		0.075		0.075		0.3
	1	Del-Tin Fiber, formerly an equity investment, became a consolidated subsidiary effective April 1, 2013. Net income for the second quarter of 2013 includes a gain on bargain purchase of $3,285,000 and a gain on previously held equity investment of $3,165,000. The fourth quarter of 2013 includes additional bargain gain recognized of $128,000, for a total of $3,413,000 for the 2013 year. (For additional information, see Note 4 – Business Combinations.)
	2	Payment of dividends is the means by which Deltic Timber Corporation makes distributions to its shareholders of profits and cash flows generated by the Company’s business operations. These dividends are declared by the Company’s Board of Directors on a quarterly basis. The Company’s dividend strategy is to grow the amount of the dividend over time, at a rate of increase that is believed to be sustainable. The timing and amount of future increases are based on the estimated trend for future earnings and cash flows, taking into account other potential uses of the Company’s capital resources including, but not limited to, acquisition opportunities, capital expenditures for existing operations, debt repayments, and repurchases of the Company’s common stock.

Significant_Accounting_Policie2

Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 01, 2013
	acre
Significant Accounting Policies [Line Items]
Area of land own by company	530,000
Cash equivalents maturity period	Three months or less
Special charges bad debt expense	$150,000	$158,000	$133,000
Balance in allowance account	123,000	172,000
Charges to allowance for write-downs	188,000	137,000	72,000
Percentage of interest holds by company			50.00%	100.00%
Maximum completion period of acquisition of LKE properties	180 days
Proceeds from sales of land deposited with LKE intermediary	0	0
Land lease term period	1 year
Deferred hunting lease revenue	2,009,000	1,684,000
Deferred mineral lease revenue	1,140,000	2,085,000
Accrued property tax expenses	1,894,000	1,798,000
Advertising Costs	764,000	716,000	732,000
Other noncurrent liabilities [Member]
Significant Accounting Policies [Line Items]
Deferred mineral lease revenue	383,000	649,000
Other current liabilities [Member]
Significant Accounting Policies [Line Items]
Deferred mineral lease revenue	$757,000	$1,436,000
Roads constructed and other land improvements [Member]
Significant Accounting Policies [Line Items]
Estimated useful life	10 years

Inventories_Inventories_Detail

Inventories - Inventories (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventories
Supplies	$1,355	$2,424
Inventory	11,494	12,439
Logs [Member]
Inventories
Raw materials	772	1,612
Del-Tin - wood fiber [Member]
Inventories
Raw materials	384	440
Lumber [Member]
Inventories
Finished goods	4,168	4,145
Medium density fiberboard [Member]
Inventories
Finished goods	3,889	3,110
Finished goods - consigned	$926	$708

Prepaid_Expenses_and_Other_Cur2

Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Prepaid Expense and Other Assets, Current [Abstract]
Short-term deferred tax assets	$2,087	$1,901
Refundable income taxes	2,537	109
Prepaid expenses	654	692
Other current assets	686	453
Prepaid expenses and other current assets	$5,964	$3,155

Business_Combinations_Addition

Business Combinations - Additional Information (Detail) (USD $)	3 Months Ended												12 Months Ended			0 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 01, 2013
Business Acquisition [Line Items]
Cash payment													$0	$5,170,000	$0
Gain on previously held equity interest							3,165,000						0	3,165,000	0
Gain on bargain purchase					128,000		3,285,000						0	3,413,000	0
Net sales	55,070,000	58,301,000	58,605,000	55,379,000	48,372,000	56,520,000	53,247,000	41,563,000	36,665,000	36,499,000	37,105,000	30,639,000	227,355,000	199,702,000	140,908,000
Del-Tin Fiber [Member]
Business Acquisition [Line Items]
Percentage membership interest of Del-Tin Fiber LLC																50.00%
Effective date of Acquisition																1-Apr-13
Total consideration																20,000,000
Cash payment													0	5,170,000		5,170,000
Annual production capacity																150,000,000
Percentage of company owning																100.00%
Long-term liabilities																29,000,000
Outstanding industrial bonds due																2027
Gain on previously held equity interest														3,165,000
Fair value of previously held investment in Del-Tin Fiber														10,786,000		10,786,000
Business combination on over carrying value								7,621,000
Business acquisition on company owned equity method investment																50.00%
Weight average cost of capital																15.00%
Gain on bargain purchase													0	3,413,000		3,413,000
Net sales														47,812,000
Net income														$3,068,000

Business_Combinations_Purchase

Business Combinations - Purchase Price Allocated to Net Tangible and Intangible Assets (Detail) (USD $)	3 Months Ended		12 Months Ended			0 Months Ended
	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 01, 2013
Loans At Acquisition Date [Line Items]
Cash paid			$0	($5,170,000)	$0
Gain on bargain purchase	128,000	3,285,000	0	3,413,000	0
Del-Tin Fiber [Member]
Loans At Acquisition Date [Line Items]
Accounts receivable						4,229,000
Inventories						4,805,000
Other current assets						360,000
Property, plant, and equipment						40,960,000
Intangible assets						1,700,000
Other assets						171,000
Current liabilities						-1,653,000
Deferred tax liabilities						-2,203,000
Long-term liabilities						-29,000,000
Net assets acquired						19,369,000
Cash paid			0	-5,170,000		-5,170,000
Fair value of previously held investment in Del-Tin Fiber				-10,786,000		-10,786,000
Gain on bargain purchase			$0	$3,413,000		$3,413,000
Del-Tin Fiber [Member] | Internally developed software [Member]
Loans At Acquisition Date [Line Items]
Acquired intangible assets useful life						3 years

Business_Combinations_Summariz

Business Combinations - Summarizes Combined Results of Operations on Pro Forma Basis (Detail) (Del-Tin Fiber [Member], USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Del-Tin Fiber [Member]
Business Acquisition [Line Items]
Net sales	$217,268	$207,446
Net income	$21,193	$8,846
Basic earnings per common share	$1.69	$0.71
Diluted earnings per common share	$1.68	$0.70

Timber_and_Timberlands_Summary

Timber and Timberlands - Summary of Timber and Timberlands (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Purchased stumpage inventory	$1,620	$2,388
Timberlands	155,704	102,609
Fee timber	322,714	253,768
Logging facilities	2,720	2,628
Gross	482,758	361,393
Less accumulated cost of fee timber harvested and facilities depreciation	-118,670	-113,056
Timber and timberlands - net	364,410	248,833
Strategic timber and timberlands [Member]
Property, Plant and Equipment [Line Items]
Timber and timberlands - net	364,088	248,337
Non-strategic timber and timberlands [Member]
Property, Plant and Equipment [Line Items]
Timber and timberlands - net	$322	$496

Timber_and_Timberlands_Additio

Timber and Timberlands - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	acre	acre
Timber And Timberlands Textual [Abstract]
Timber and timberlands acquired	72,170	7,004
Cash payments for timberland acquisition expenditures	$118,203,000	$8,919,000	$14,527,000
Acres of timber land available for sale	655	1,000
Gains on sales of timberland	857,000	1,715,000	1,910,000
Non-monetary land exchanges	0	0	0
Cost of fee timber harvested	5,544,000	4,494,000	4,497,000
Logging facilities depreciation	$91,000	$92,000	$94,000

Property_Plant_and_Equipment_P

Property, Plant, and Equipment - Property, Plant, and Equipment (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	184,431	$178,122
Less accumulated depreciation	-110,267	-102,863
Property, plant, and equipment, net	74,164	75,259
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	947	947
Land improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	8,163	8,835
Land improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, useful life	10 years
Land improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, useful life	20 years
Buildings and structures [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	22,680	22,599
Buildings and structures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, useful life	10 years
Buildings and structures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, useful life	20 years
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	152,641	$145,741
Machinery and equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, useful life	3 years
Machinery and equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, useful life	15 years

Property_Plant_and_Equipment_A

Property, Plant, and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Depreciation of property, plant, and equipment charged to operations	$12,707	$10,544	$6,051
Gains/(losses) on disposals or retirements of assets included in operating income	($1,071)	$362	($128)

Deferred_Revenues_and_Other_Ac2

Deferred Revenues and Other Accrued Liabilities - Deferred Revenues and Other Accrued Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Revenue Disclosure [Abstract]
Deferred revenues - current	$3,310	$3,697
Vacation accrual	1,312	1,290
Deferred compensation	1,166	3,442
All other current liabilities	1,435	1,901
Deferred revenues and other accrued liabilities	$7,223	$10,330

Other_Noncurrent_Liabilities_O

Other Noncurrent Liabilities - Other Noncurrent Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other Liabilities Disclosure [Abstract]
Accumulated postretirement benefit obligation	$12,343	$10,391
Excess retirement plan	9,372	4,457
Accrued pension liability	14,955	6,383
Deferred revenue - long-term portion	383	649
Uncertain tax positions liability	0	1,185
All other noncurrent payables	2,287	2,678
Other noncurrent liabilities, net	$39,340	$25,743

Credit_Facilities_Additional_I

Credit Facilities - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Sun Trust Bank [Member] | Revolving credit facility [Member]
Credit Facilities [Line Items]
Amount available on credit facility	$430,000,000
Option to increase in the amount of aggregate revolving commitments	50,000,000
Credit facility occurred date	18-Nov-14
Credit facility expiry date	18-Nov-19
Amendment fees incurred	700,000
Remaining unamortized prior costs	967,000
Outstanding borrowings	134,000,000	21,000,000
Amount available in excess of all borrowings outstanding	296,000,000	319,000,000
Interest on borrowings	Base rate or an adjusted Eurodollar rate plus an applicable margin
Maximum leverage ratio	0.65%
Sun Trust Bank [Member] | Minimum [Member] | Revolving credit facility [Member]
Credit Facilities [Line Items]
Timber market value	175.00%
Commitment fee payable per annum	0.20%
Sun Trust Bank [Member] | Maximum [Member] | Revolving credit facility [Member]
Credit Facilities [Line Items]
Commitment fee payable per annum	0.35%
Bancorp South [Member]
Credit Facilities [Line Items]
Outstanding borrowings	620,000	554,000
Bancorp South [Member] | short-term credit facility [Member]
Credit Facilities [Line Items]
Credit facility expiry date	31-Dec-15
Outstanding borrowings	0	0
Amount available in excess of all borrowings outstanding	1,000,000	1,000,000
Interest on borrowings	Based upon the New York Prime rate
Amount available on short term credit facility	$1,000,000

Indebtedness_Companys_Indebted

Indebtedness - Company's Indebtedness (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Long-term debt	$203,000	$90,000
Notes payable, 1.67%*, due 2019 [Member] | Revolving credit facility [Member]
Debt Instrument [Line Items]
Long-term debt, including current maturities	134,000	21,000
Senior notes payable, 6.10%, due 2016 [Member]
Debt Instrument [Line Items]
Long-term debt, including current maturities	40,000	40,000
Union County, Arkansas Taxable Industrial Revenue Bonds, .29%*, due 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, including current maturities	$29,000	$29,000

Indebtedness_Companys_Indebted1

Indebtedness - Company's Indebtedness (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Senior notes payable, 6.10%, due 2016 [Member]
Debt Instrument [Line Items]
Debt instrument maturity year	31-Dec-16
Weighted average interest rate of notes payable	6.10%
Union County, Arkansas Taxable Industrial Revenue Bonds, .29%*, due 2027 [Member]
Debt Instrument [Line Items]
Debt instrument maturity year	31-Dec-27
Weighted average interest rate of notes payable	0.29%	0.31%
Revolving credit facility [Member] | Notes payable, 1.67%*, due 2019 [Member]
Debt Instrument [Line Items]
Debt instrument maturity year	31-Dec-19
Weighted average interest rate of notes payable	1.67%	1.54%

Indebtedness_Additional_Inform

Indebtedness - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended
	Sep. 01, 2004	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 1998
Debt Instrument [Line Items]
Percentage of Timber market value		175.00%
Scheduled maturities of long-term debt, year one		$0
Scheduled maturities of long-term debt, year two		40,000,000
Scheduled maturities of long-term debt, year three		0
Scheduled maturities of long-term debt, year four		0
Scheduled maturities of long-term debt, year five		134,000,000
Senior notes payable, 6.10%, due 2016 [Member]
Debt Instrument [Line Items]
Private placement long term debt outstanding		40,000,000	40,000,000
Weighted average interest rate of notes payable		6.10%
Maximum funded debt		0.65
Changes to financial covenants by leverage ratio		0.65
Senior notes payable, 6.10%, due 2016 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of Timber market value		175.00%
Union County, Arkansas Taxable Industrial Revenue Bonds, .29%*, due 2027 [Member]
Debt Instrument [Line Items]
Private placement long term debt outstanding		29,000,000	29,000,000
Weighted average interest rate of notes payable		0.29%	0.31%
Long-term liabilities		29,000,000
Bonds issued to complete construction of plant					60,000,000
Unpaid interest and principal due date		1-Oct-27
Retirement of bonds	$31,000,000
Average interest rate on bonds		0.29%	0.38%	0.70%

Indebtedness_Ratio_Requirement

Indebtedness - Ratio Requirements for Revolving Credit Facility and Senior Notes Payable (Detail)	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Debt Covenants [Line Items]
Total outstanding debt as a percentage of total debt allowed based on the minimum timber market value covenant	74.94%	48.24%
Covenants Requirements [Member]
Schedule Of Debt Covenants [Line Items]
Leverage ratio should be less than	0.65
Actual Ratio [Member]
Schedule Of Debt Covenants [Line Items]
Leverage ratio should be less than	0.432	0.254

Indebtedness_Ratio_Requirement1

Indebtedness - Ratio Requirements for Revolving Credit Facility and Senior Notes Payable (Parenthetical) (Detail)	Dec. 31, 2014
Debt Disclosure [Abstract]
Percentage of Timber market value	175.00%

Income_Taxes_Schedule_of_Compo

Income Taxes - Schedule of Components of Income Tax Expense/(Benefit) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Federal
Current	$9,959	$10,237	$4,743
Deferred	-961	138	-685
Total federal income tax expense (benefit)	8,998	10,375	4,058
State
Current	887	2,154	707
Deferred	-292	103	36
Total state and local income tax expense (benefit)	595	2,257	743
Income tax provision as reported	$9,593	$12,632	$4,801

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Company's income tax expense at the statutory U.S. federal rate	35.00%	35.00%	35.00%
Reversal of uncertain state income tax position	($776,000)	$0	$0
Deferred revenues other accrued liabilities for interest and penalties	$0	$621,000

Income_Taxes_Schedule_of_Recon

Income Taxes - Schedule of Reconciliation of Income Tax Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
U.S. federal income tax using statutory tax rate	$10,239	$13,588	$4,913
State tax, net of federal tax benefit	1,130	1,458	446
Permanent differences	-1,000	-1,219	-558
Tax effects resulting from:
Gain on bargain purchase	0	-1,195	0
Reversal of uncertain state income tax position	-776	0	0
Income tax provision as reported	$9,593	$12,632	$4,801

Income_Taxes_Schedule_of_Defer

Income Taxes - Schedule of Deferred Tax Assets and Deferred Tax Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets
Investment in real estate held for development and sale	$17,286	$16,914
Postretirement and other employee benefits	20,086	13,435
Other deferred tax assets	2,093	2,360
Total deferred tax assets	39,465	32,709
Deferred tax liabilities
Timber and timberlands	-27,191	-26,158
Property, plant, and equipment	-11,021	-11,838
Other deferred tax liabilities	-268	-326
Total deferred tax liabilities	-38,480	-38,322
Net deferred tax assets/(liabilities)	$985	($5,613)

Income_Taxes_Schedule_of_Defer1

Income Taxes - Schedule of Deferred Tax Assets and Liabilities Classified in Accompanying Consolidated Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Current tax assets	$2,087	$1,901
Long-term tax liabilities	-1,102	-7,514
Net deferred tax assets/(liabilities)	$985	($5,613)

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Balance at January 1	$1,185	$1,331
Lapse of statute	-1,185	-146
Balance at December 31	$0	$1,185

Stockholders_Rights_Plan_Addit

Stockholders Rights Plan - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Stockholders Rights Plan Textual [Abstract]
Stockholders right plan amended and increase the exercise price	$200
Person becoming beneficial owner	15.00%

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Fair Value Measurements for Financial Liabilities Accounted on a Recurring Basis (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Liabilities
Nonqualified employee savings plan	$1,504
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member]
Liabilities
Nonqualified employee savings plan	1,504
Significant Observable Inputs Level 2 [Member]
Liabilities
Nonqualified employee savings plan	0
Significant Unobservable Inputs Level 3 [Member]
Liabilities
Nonqualified employee savings plan	$0

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Carrying Amounts and Estimated Fair Values of Financial Instruments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Financial liabilities
Long-term debt, including current maturities, Carrying Amount	$203,000	$90,000
Long-term debt, including current maturities, Estimated Fair Value	$207,077	$94,534

Concentration_of_Credit_Risks_

Concentration of Credit Risks - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Risks and Uncertainties [Abstract]
Accounts receivables	$0	$0

Other_Comprehensive_Income_Dis2

Other Comprehensive Income Disclosures - Changes in Accumulated Other Comprehensive Loss by Component (Net of Tax) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, January 1	($2,679)
Net gain (loss) arising during period	-8,895	10,973	-5,131
Ending Balance, December 31	-11,411	-2,679
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, January 1	-2,679	-14,103	-9,729
Amounts reclassified from AOCL	163	451	757
Net gain (loss) arising during period	-8,895	10,973	-5,131
Net current period other comprehensive income (loss)	-8,732	11,424	-4,374
Ending Balance, December 31	-11,411	-2,679	-14,103
Accumulated Defined Benefit Plans Adjustment [Member] | Defined Benefit Funded Retirement Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, January 1	-2,410	-9,553	-8,124
Amounts reclassified from AOCL	111	529	608
Net gain (loss) arising during period	-5,316	6,614	-2,037
Net current period other comprehensive income (loss)	-5,205	7,143	-1,429
Ending Balance, December 31	-7,615	-2,410	-9,553
Accumulated Defined Benefit Plans Adjustment [Member] | Defined Benefit Unfunded Retirement Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, January 1	-482	-3,380	-855
Amounts reclassified from AOCL	173	38	226
Net gain (loss) arising during period	-2,755	2,860	-2,751
Net current period other comprehensive income (loss)	-2,582	2,898	-2,525
Ending Balance, December 31	-3,064	-482	-3,380
Accumulated Defined Benefit Plans Adjustment [Member] | Other Post-Retirement Benefit Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, January 1	213	-1,170	-750
Amounts reclassified from AOCL	-121	-116	-77
Net gain (loss) arising during period	-824	1,499	-343
Net current period other comprehensive income (loss)	-945	1,383	-420
Ending Balance, December 31	($732)	$213	($1,170)

Other_Comprehensive_Income_Dis3

Other Comprehensive Income Disclosures - Reclassification Out of Accumulated Other Comprehensive Loss (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service costs	$10	$7	$7
Amortization of actuarial losses	457	934	1,438
Amortization of plan amendment	-199	-199	-199
Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service costs	10	7	7
Amortization of actuarial losses	457	934	1,438
Amortization of plan amendment	-199	-199	-199
Total before tax	268	742	1,246
Income tax benefit/(expense)	-105	-291	-489
Total reclassifications - net of tax	163	451	757
Accumulated Defined Benefit Plans Adjustment [Member] | Defined Benefit Funded Retirement Plan [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service costs	17	18	18
Amortization of actuarial losses	165	852	982
Amortization of plan amendment	0	0	0
Total before tax	182	870	1,000
Income tax benefit/(expense)	-71	-341	-392
Total reclassifications - net of tax	111	529	608
Accumulated Defined Benefit Plans Adjustment [Member] | Defined Benefit Unfunded Retirement Plan [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service costs	-7	-11	-11
Amortization of actuarial losses	292	74	383
Amortization of plan amendment	0	0	0
Total before tax	285	63	372
Income tax benefit/(expense)	-112	-25	-146
Total reclassifications - net of tax	173	38	226
Accumulated Defined Benefit Plans Adjustment [Member] | Other Post-Retirement Benefit Plan [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service costs	0	0	0
Amortization of actuarial losses	0	8	73
Amortization of plan amendment	-199	-199	-199
Total before tax	-199	-191	-126
Income tax benefit/(expense)	78	75	49
Total reclassifications - net of tax	($121)	($116)	($77)

Other_Comprehensive_Income_Dis4

Other Comprehensive Income Disclosures - Tax Effects by Component (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect [Abstract]
Gains/(losses) arising during the period, Before Tax Amount	($14,636)	$18,054	($8,442)
Amortization of prior service costs, Before Tax Amount	10	7	7
Amortization of actuarial losses, Before Tax Amount	457	934	1,438
Amortization of plan amendment, Before tax amount	-199	-199	-199
Total before tax	-14,368	18,796	-7,196
Gains/(losses) arising during the period, Tax (expense) or benefit	5,741	-7,081	3,311
Amortization of prior service costs, Tax (Expenses) or benefits	-4	-3	-3
Amortization of actuarial losses, Tax (Expenses) or benefits	-179	-366	-564
Amortization of plan amendment, Tax (Expenses) or benefits	78	78	78
Total Tax (Expenses) or benefits	5,636	-7,372	2,822
Gains/(losses) arising during the period	-8,895	10,973	-5,131
Amortization of prior service costs	6	4	4
Amortization of actuarial losses	278	568	874
Amortization of plan amendment, Net of Tax Amount	-121	-121	-121
Total reclassifications - net of tax	($8,732)	$11,424	($4,374)

Employee_and_Retiree_Benefit_P2

Employee and Retiree Benefit Plans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employee service hours	1000 hours
Employment commencement period	Both the 1,000 hours requirement and the employment requirement for each twelve-month period.
Service period of employee	12 months
Amendment of other defined benefit postretirement plans	$1,136,000
Defined benefit obligations, outstanding	250,000,000
Defined benefit plan assumptions	The discount rate assumption used by the Company to measure benefit obligations and net periodic expenses is based on a spot-rate yield curve using current market data for corporate bonds at the measurement date and is used to determine the present value of the expected future cash flows at the measurement date. Additionally, a single rate is determined so that the present value of the benefit obligations using the single rate equals the present value using the spot rate yield curve. The yield curve only includes bonds that meet the following criteria: (1) have maturities between 6 months and 30 years; (2) are noncallable, nonputable, and do not have a sinking fund provision; (3) have fixed coupon payments with a single payment at maturity; (4) have more than $250 million par outstanding; (5) are U.S. dollar-denominated bonds; and (6) have an average rating of AA- (S&P/Fitch) or Aa3 (Moodybs) and higher.
Percentage of expected long-term rate of return on pension plan	7.50%
Health care inflation cost assumed to increase at an annual rate	5.00%
A one percentage-point increase in the assumed health care cost trend rate increases the aggregate service and interest cost components	172,000
A one percentage-point increase in the assumed health care cost trend rate and the benefit obligation	2,171,000
One percentage-point decrease in the assumed rate	135,000
One percentage-point decrease in the assumed rate and the benefit obligation	1,713,000
Planed Asset Allocation Levels, Minimum	45.00%
Planed Asset Allocation Levels, Maximum	70.00%
Plan assets held in the securities	2.50%
Plan assets were invested in mortgage-backed securities	3.00%
Minimum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit obligations maturity date	6 months
Maximum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit obligations maturity date	30 years
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Planed Asset Allocation Levels, Minimum	25.00%
Planed Asset Allocation Levels, Maximum	55.00%
Alternative Investment Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Planed Asset Allocation Levels, Minimum	0.00%
Planed Asset Allocation Levels, Maximum	15.00%
Cash and Cash Equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Planed Asset Allocation Levels, Minimum	0.00%
Planed Asset Allocation Levels, Maximum	5.00%
Large Cap Market [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Planed Asset Allocation Levels, Minimum	40.00%
Planed Asset Allocation Levels, Maximum	60.00%
Mid and Small Cap Equity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Planed Asset Allocation Levels, Minimum	5.00%
Planed Asset Allocation Levels, Maximum	15.00%
International Equity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Planed Asset Allocation Levels, Minimum	0.00%
Planed Asset Allocation Levels, Maximum	25.00%
Planed Asset Allocation Levels	40.00%
Thrift Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	829,000	792,000	584,000
Pension Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss and net prior service cost for retirement pension plan	4,000
Percentage of expected long-term rate of return on pension plan	7.50%	7.50%	7.50%
Other Post-Retirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss and net estimated prior service cost for retirement pension plan	46,000
Contributions towards the defined benefit funded retirement plan	355,000
Employer contributions	328,000	201,000
Defined Benefit Funded Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected expense	2,148,000
Contributions towards the defined benefit funded retirement plan	1,200,000
Employer contributions	1,200,000	1,200,000
Defined Benefit Unfunded Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions towards the defined benefit funded retirement plan	272,000
Employer contributions	$255,000	$239,000

Employee_and_Retiree_Benefit_P3

Employee and Retiree Benefit Plans - Plan Benefit Obligations, Fair Value of Plan Assets, and Funded Status (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in plan assets
Fair value of plan assets at end of period	$32,795	$30,627
Amounts recognized in the balance sheet
Noncurrent liability	-9,372	-4,457
Defined Benefit Funded Retirement Plan [Member]
Change in benefit obligation
Benefit obligation at beginning of period	37,010	42,716
Service cost	1,476	1,549	1,630
Interest cost	1,839	1,557	1,622
Participant contributions	0	0
Actuarial (gain)/loss	8,626	-7,672
Benefits paid	-1,201	-1,140
Benefit obligation at end of period	47,750	37,010	42,716
Change in plan assets
Fair value of plan assets at beginning of period	30,627	25,463
Actual return on plan assets	2,327	5,237
Employer contributions	1,200	1,200
Participant contributions	0	0
Benefits paid	-1,201	-1,140
Expenses	-158	-133
Fair value of plan assets at end of period	32,795	30,627	25,463
Funded status of plans	-14,955	-6,383
Amounts recognized in the balance sheet
Current liability	0	0
Noncurrent liability	-14,955	-6,383
Deferred income taxes - net	5,866	2,504
Accumulated other comprehensive (income)/loss	7,615	2,410
Amounts recognized in accumulated other comprehensive loss
Net unrecognized (gain)/loss	12,525	3,942
Unrecognized prior service cost/(credit)	4	21
Tax effects	-4,914	-1,553
Amounts recognized in accumulated other comprehensive loss, Total	7,615	2,410
Assumptions used in measurement of benefit obligations
Weighted average discount rate	4.21%	4.84%
Rate of compensation increase	4.00%	4.00%
Accumulated benefit obligations at year end	40,720	32,272
Defined Benefit Unfunded Retirement Plan [Member]
Change in benefit obligation
Benefit obligation at beginning of period	4,690	9,299
Service cost	302	143	364
Interest cost	373	192	355
Participant contributions	0	0
Actuarial (gain)/loss	4,534	-4,705
Benefits paid	-255	-239
Benefit obligation at end of period	9,644	4,690	9,299
Change in plan assets
Fair value of plan assets at beginning of period	0	0
Actual return on plan assets	0	0
Employer contributions	255	239
Participant contributions	0	0
Benefits paid	-255	-239
Expenses	0	0
Fair value of plan assets at end of period	0	0	0
Funded status of plans	-9,644	-4,690
Amounts recognized in the balance sheet
Current liability	-272	-233
Noncurrent liability	-9,372	-4,457
Deferred income taxes - net	3,783	1,840
Accumulated other comprehensive (income)/loss	3,064	482
Amounts recognized in accumulated other comprehensive loss
Net unrecognized (gain)/loss	5,041	799
Unrecognized prior service cost/(credit)	0	-7
Tax effects	-1,977	-310
Amounts recognized in accumulated other comprehensive loss, Total	3,064	482
Assumptions used in measurement of benefit obligations
Weighted average discount rate	4.21%	4.84%
Rate of compensation increase	4.00%	4.00%
Accumulated benefit obligations at year end	6,792	4,660
Other Post-Retirement Benefit Plan [Member]
Change in benefit obligation
Benefit obligation at beginning of period	10,756	12,542
Service cost	418	450	455
Interest cost	497	431	467
Participant contributions	88	88
Actuarial (gain)/loss	1,355	-2,466
Benefits paid	-416	-289
Benefit obligation at end of period	12,698	10,756	12,542
Change in plan assets
Fair value of plan assets at beginning of period	0	0
Actual return on plan assets	0	0
Employer contributions	328	201
Participant contributions	88	88
Benefits paid	-416	-289
Expenses	0	0
Fair value of plan assets at end of period	0	0	0
Funded status of plans	-12,698	-10,756
Amounts recognized in the balance sheet
Current liability	-355	-365
Noncurrent liability	-12,343	-10,391
Deferred income taxes - net	4,981	4,219
Accumulated other comprehensive (income)/loss	732	-213
Amounts recognized in accumulated other comprehensive loss
Net unrecognized (gain)/loss	1,231	-124
Unrecognized prior service cost/(credit)	-46	-245
Tax effects	-453	156
Amounts recognized in accumulated other comprehensive loss, Total	$732	($213)
Assumptions used in measurement of benefit obligations
Weighted average discount rate	4.25%	4.85%

Employee_and_Retiree_Benefit_P4

Employee and Retiree Benefit Plans - Retirement Expense and Other Postretirement Benefits Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Funded Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$1,476	$1,549	$1,630
Interest cost	1,839	1,557	1,622
Expected return on plan assets	-2,290	-1,894	-1,692
Amortization of prior service cost	17	18	18
Amortization of actuarial loss	165	852	982
Net periodic benefit cost	1,207	2,082	2,560
Defined Benefit Unfunded Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	302	143	364
Interest cost	373	192	355
Amortization of prior service cost	-7	-11	-11
Amortization of actuarial loss	292	74	383
Net periodic benefit cost	960	399	1,091
Other Post-Retirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	418	450	455
Interest cost	497	431	467
Amortization of prior service cost	-199	-199	-199
Amortization of actuarial loss	0	8	73
Net periodic benefit cost	$716	$690	$796

Employee_and_Retiree_Benefit_P5

Employee and Retiree Benefit Plans - Assumptions Used to Determine Net Periodic Benefit Cost - Pension Plans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assumptions used to determine net periodic benefit cost - defined benefit pension plans
Expected long-term rate of return on plan assets	7.50%
Assumptions used to determine net periodic benefit cost - other postretirement plan
Expected long-term rate of return on plan assets	7.50%
Other changes in plan assets and benefit obligations recognized in other comprehensive (income)/loss
Net unrecognized loss/(gain)	$14,636	($18,054)	$8,442
Amortization of prior service credit	-10	-7	-7
Amortization of actuarial losses	-457	-934	-1,438
Amortization of plan amendment	199	199	199
Tax effect of changes	-5,636	7,372	-2,822
Total recognized in other comprehensive (income)/loss	$8,732	($11,424)	$4,374
Pension Plans [Member]
Assumptions used to determine net periodic benefit cost - defined benefit pension plans
Weighted average discount rate	4.84%	3.94%	4.34%
Expected long-term rate of return on plan assets	7.50%	7.50%	7.50%
Rate of compensation increase	4.00%	4.00%	4.00%
Assumptions used to determine net periodic benefit cost - other postretirement plan
Weighted average discount rate	4.84%	3.94%	4.34%
Expected long-term rate of return on plan assets	7.50%	7.50%	7.50%
Rate of compensation increase	4.00%	4.00%	4.00%
Other Post-Retirement Benefit Plan [Member]
Assumptions used to determine net periodic benefit cost - defined benefit pension plans
Weighted average discount rate	4.85%	3.90%	4.30%
Assumptions used to determine net periodic benefit cost - other postretirement plan
Weighted average discount rate	4.85%	3.90%	4.30%

Employee_and_Retiree_Benefit_P6

Employee and Retiree Benefit Plans - Estimated Benefit Payments by Year (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Defined Benefit Funded Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
2015	$1,351
2016	1,421
2017	1,535
2018	1,668
2019	1,835
2020 - 2024	12,359
Defined Benefit Unfunded Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
2015	272
2016	270
2017	267
2018	264
2019	261
2020 - 2024	2,849
Other Post-Retirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
2015	355
2016	369
2017	405
2018	447
2019	498
2020 - 2024	$3,180

Employee_and_Retiree_Benefit_P7

Employee and Retiree Benefit Plans - Fair Value Investments Plan (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	100.00%	100.00%
Total plan investments at fair value	$32,795	$30,627
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	4.50%	3.20%
Total plan investments at fair value	1,470	984
Other Plan Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	0.10%	0.20%
Total plan investments at fair value	40	54
Equity Securities Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	0.30%	0.40%
Total plan investments at fair value	105	111
Equity Securities Materials and Industrials [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	2.00%	2.60%
Total plan investments at fair value	652	784
Equity Securities Consumer [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	3.90%	4.70%
Total plan investments at fair value	1,274	1,435
Equity Securities Healthcare [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	2.60%	2.50%
Total plan investments at fair value	854	771
Equity Securities Financials [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	0.60%	0.80%
Total plan investments at fair value	201	259
Equity Securities Information Tech [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	4.60%	4.60%
Total plan investments at fair value	1,503	1,409
Equity Securities Foreign Stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	1.00%	1.00%
Total plan investments at fair value	319	302
Us Govt and Agency Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	15.20%	12.30%
Total plan investments at fair value	5,001	3,775
Corporate Debt Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	7.20%	10.70%
Total plan investments at fair value	2,370	3,287
Mutual Funds Dividend and Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	28.40%	29.50%
Total plan investments at fair value	9,327	9,042
Mutual Funds International and Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	5.60%	5.90%
Total plan investments at fair value	1,835	1,798
Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	2.30%
Total plan investments at fair value	742
Exchange Traded Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	15.00%	14.80%
Total plan investments at fair value	4,913	4,539
Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	6.70%	6.80%
Total plan investments at fair value	2,189	2,077
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	80.60%	75.50%
Total plan investments at fair value	26,443	23,121
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	1,470	984
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Other Plan Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	40	54
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Equity Securities Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	105	111
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Equity Securities Materials and Industrials [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	652	784
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Equity Securities Consumer [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	1,274	1,435
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Equity Securities Healthcare [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	854	771
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Equity Securities Financials [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	201	259
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Equity Securities Information Tech [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	1,503	1,409
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Equity Securities Foreign Stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	319	302
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Us Govt and Agency Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	3,208	1,633
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Corporate Debt Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Mutual Funds Dividend and Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	9,327	9,042
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Mutual Funds International and Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	1,835	1,798
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	742
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Exchange Traded Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	4,913	4,539
Quoted Prices in Active Markets for Identical Liabilities Inputs Level 1 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	12.70%	17.70%
Total plan investments at fair value	4,163	5,429
Significant Observable Inputs Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Other Plan Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Equity Securities Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Equity Securities Materials and Industrials [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Equity Securities Consumer [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Equity Securities Healthcare [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Equity Securities Financials [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Equity Securities Information Tech [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Equity Securities Foreign Stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Us Govt and Agency Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	1,793	2,142
Significant Observable Inputs Level 2 [Member] | Corporate Debt Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	2,370	3,287
Significant Observable Inputs Level 2 [Member] | Mutual Funds Dividend and Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Mutual Funds International and Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0
Significant Observable Inputs Level 2 [Member] | Exchange Traded Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Observable Inputs Level 2 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent of fair value hierarchy	6.70%	6.80%
Total plan investments at fair value	2,189	2,077
Significant Unobservable Inputs Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Other Plan Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Equity Securities Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Equity Securities Materials and Industrials [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Equity Securities Consumer [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Equity Securities Healthcare [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Equity Securities Financials [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Equity Securities Information Tech [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Equity Securities Foreign Stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Us Govt and Agency Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Corporate Debt Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Mutual Funds Dividend and Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Mutual Funds International and Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0
Significant Unobservable Inputs Level 3 [Member] | Exchange Traded Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	0	0
Significant Unobservable Inputs Level 3 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan investments at fair value	$2,189	$2,077

Employee_and_Retiree_Benefit_P8

Employee and Retiree Benefit Plans - Activity in Level 3 Investments (Detail) (Significant Unobservable Inputs Level 3 [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Significant Unobservable Inputs Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$2,077	$0
Actual return on plan assets:
Relating to assets still held at the reporting date	112	77
Purchases, sales, and settlements	0	2,000
Ending balance	$2,189	$2,077

Incentive_Plans_Additional_Inf

Incentive Plans - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum number of shares awarded as restricted stock	75,000
Options and stock appreciation rights in calendar year	50,000
Stock Based Compensation Expense	$3,238	$2,797	$2,298
Income tax benefit	160	409	607
Options granted period	10 years
Option vested	One-fourth
Subsequent period of options granted	4 years
Option Price Upper limit	$34.41
Option Price lower limit	$71.35
Intrinsic value of options exercised	124	513	682
Vesting period of restricted stock units	4 years
2002 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for issuance under the 2002 plan	1,800,000
Number of shares available for award under 2002 plan	845,118
Cash Incentive Compensation Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expenses towards cash incentive awards	586	2,549	2,014
Accrued provisions for cash incentive awards	400	2,631
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested stock	966
Cost recognized over a weighted-average period	1 year 7 months 6 days
Nonvested Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested stock	2,453
Cost recognized over a weighted-average period	1 year 8 months 12 days
Nonvested Restricted Stock Performance Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested stock	$2,083
Cost recognized over a weighted-average period	1 year 8 months 12 days
Other Stock Based Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Other stock-based awards	0

Incentive_Plans_Valuation_of_S

Incentive Plans - Valuation of Stock Options and Restricted Stock Performance Units (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected term of options (in years)	6 years 3 months 7 days	6 years 3 months 7 days	6 years 3 months 7 days
Weighted expected volatility	37.38%	37.78%	38.78%
Dividend yield	0.55%	0.58%	0.61%
Risk-free interest rate - performance restricted shares	1.23%	0.60%	0.60%
Risk-free interest rate - stock options	2.99%	1.98%	2.00%
Stock price as of valuation date	$63.21	$71.35	$67.67
Restricted performance share valuation	$80.56	$87.74	$90.61
Grant date fair value - stock options	$21.87	$26.20	$24.92

Incentive_Plans_Summary_of_Sto

Incentive Plans - Summary of Stock Option (Detail) (Stock Options [Member], USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding Shares, beginning balance	131,456
Shares, Granted	26,611
Shares, Exercised	-5,854
Shares, Forfeited/expired	-460
Outstanding Shares, ending balance	151,753
Shares, Exercisable	87,552
Outstanding Weighted Average Exercise Price, beginning	$59.64
Weighted Average Exercise Price, Granted	$63.35
Weighted Average Exercise Price, Exercised	$43.30
Weighted Average Exercise Price, Forfeited/expired	$36.61
Outstanding Weighted Average Exercise Price, ending	$60.99
Outstanding Weighted Average Exercise Price, Exercisable	$56.96
Outstanding Weighted Average Remaining Contractual Term (Years), Ending	6 years 1 month 6 days
Weighted Average Remaining Contractual Term, Exercisable	4 years 7 months 6 days
Outstanding Aggregate Intrinsic Value, Ending	$1,197
Aggregate Intrinsic Values, Exercisable	$1,020

Incentive_Plans_Summary_of_Sto1

Incentive Plans - Summary of Stock Options Outstanding (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Lower Limit	$71.35
Range of Exercise Prices Upper Limit	$34.41
Number of Options, Options Outstanding	151,753
Number of Options, Options Exercisable	87,552
Range One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Lower Limit	$31
Range of Exercise Prices Upper Limit	$35
Number of Options, Options Outstanding	2,766
Average Life in Years, Options Outstanding	4 years 1 month 6 days
Average Exercise Price, Options Outstanding	$34.41
Number of Options, Options Exercisable	2,766
Average Exercise Price, Options Exercisable	$34.41
Range Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Lower Limit	$41
Range of Exercise Prices Upper Limit	$45
Number of Options, Options Outstanding	14,020
Average Life in Years, Options Outstanding	5 years 1 month 6 days
Average Exercise Price, Options Outstanding	$44.84
Number of Options, Options Exercisable	14,020
Average Exercise Price, Options Exercisable	$44.84
Range Three [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Lower Limit	$51
Range of Exercise Prices Upper Limit	$55
Number of Options, Options Outstanding	31,848
Average Life in Years, Options Outstanding	1 year 10 months 24 days
Average Exercise Price, Options Outstanding	$53.01
Number of Options, Options Exercisable	31,848
Average Exercise Price, Options Exercisable	$53.01
Range Four [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Lower Limit	$56
Range of Exercise Prices Upper Limit	$65
Number of Options, Options Outstanding	52,462
Average Life in Years, Options Outstanding	7 years 7 months 6 days
Average Exercise Price, Options Outstanding	$63.38
Number of Options, Options Exercisable	19,727
Average Exercise Price, Options Exercisable	$63.54
Range Five [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Lower Limit	$66
Range of Exercise Prices Upper Limit	$75
Number of Options, Options Outstanding	50,657
Average Life in Years, Options Outstanding	7 years 7 months 6 days
Average Exercise Price, Options Outstanding	$69.45
Number of Options, Options Exercisable	19,191
Average Exercise Price, Options Exercisable	$68.85

Incentive_Plans_Summary_of_Non

Incentive Plans - Summary of Nonvested Restricted Stock (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted Average Grant-Date Fair Value Nonvested, Granted	$80.56	$87.74	$90.61
Nonvested Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares Nonvested, Beginning Balance	79,591
Shares Nonvested, Granted	24,951
Shares Nonvested, Vested	-19,132
Shares Nonvested, Ending Balance	85,410
Weighted Average Grant-Date Fair Value Nonvested, Beginning Balance	$62.31
Weighted Average Grant-Date Fair Value Nonvested, Granted	$63.30
Weighted Average Grant-Date Fair Value Nonvested, Vested	$44.84
Weighted Average Grant-Date Fair Value Nonvested, Ending Balance	$66.51

Incentive_Plans_Summary_of_Non1

Incentive Plans - Summary of Nonvested Restricted Stock Performance Units (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted Average Grant-Date Fair Value Nonvested, Granted	$80.56	$87.74	$90.61
Nonvested Restricted Stock Performance Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares Nonvested, Beginning Balance	52,625
Shares Nonvested, Granted	16,613
Shares Nonvested, Units not meeting vesting conditions	-12,652
Shares Nonvested, Ending Balance	56,586
Weighted Average Grant-Date Fair Value Nonvested, Beginning Balance	$80.87
Weighted Average Grant-Date Fair Value Nonvested, Granted	$80.70
Weighted Average Grant-Date Fair Value Nonvested, Units not meeting vesting conditions	$58.66
Weighted Average Grant-Date Fair Value Nonvested, Ending Balance	$85.78

Supplemental_Cash_Flow_Disclos

Supplemental Cash Flow Disclosures - Interest and Income Taxes Information Concerning Cash Flows (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental Cash Flow Information [Abstract]
Income taxes paid in cash	$14,976	$11,042	$4,227
Interest paid	5,420	3,954	3,571
Interest capitalized	($70)	($53)	($36)

Supplemental_Cash_Flow_Disclos1

Supplemental Cash Flow Disclosures - Non-cash Investing and Financing Activities (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Issuance of restricted stock	$1,290	$935	$1,393
Capital expenditures accrued, not paid	738	1,271	79
Fair value of Del-Tin Fiber net assets acquired	$0	$19,369	$0

Supplemental_Cash_Flow_Disclos2

Supplemental Cash Flow Disclosures - (Increases)/Decreases in Operating Working Capital Other Than Cash and Cash Equivalents (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract]
Trade accounts receivable	($1,756)	$2,178	($457)
Other receivables	8	-6	-12
Inventories	945	-2,740	-541
Prepaid expenses and other current assets	-2,543	-184	963
Trade accounts payable	-2,123	3,701	35
Accrued taxes other than income taxes	-61	216	-19
Deferred revenues and other accrued liabilities	-3,644	2,718	2,486
Other Current Assets and Liabilities, Net	($9,174)	$5,883	$2,455

Supplemental_Cash_Flows_Disclo2

Supplemental Cash Flows Disclosures - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Cash Flows [Abstract]
Deferred long-term mineral lease	$266	$1,635	$1,767
Total cash payment received from deferred mineral lease rental	$711	$30	$450

Earnings_per_Share_Computation

Earnings per Share - Computation of Earnings Per Share (Detail) (USD $)	3 Months Ended												12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Net earnings allocated to common stock													$19,445	$25,924	$9,144
Net earnings allocated to participating securities													217	268	91
Net income allocated to common stock and participating securities	$3,479	$5,974	$5,298	$4,911	$2,337	$5,813	$11,268	$6,774	$2,404	$3,218	$3,516	$97	$19,662	$26,192	$9,235
Weighted average number of common shares used in basic EPS													12,497	12,566	12,525
Effect of dilutive stock awards													56	58	63
Weighted average number of common shares and dilutive potential common stock used in EPS assuming dilution													12,553	12,624	12,588
Earnings per common share
Basic	$0.28	$0.47	$0.42	$0.39	$0.18	$0.46	$0.89	$0.53	$0.19	$0.25	$0.28	$0.01	$1.56	$2.06	$0.73
Assuming dilution	$0.28	$0.47	$0.42	$0.39	$0.18	$0.46	$0.88	$0.53	$0.19	$0.25	$0.28	$0.01	$1.55	$2.05	$0.73

Earnings_per_Share_Information

Earnings per Share - Information about Potentially Dilutive Securities Outstanding (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares outstanding not included in the computation of diluted earnings per share	76,968	50,197	26,459
Restricted Performance Shares [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares outstanding not included in the computation of diluted earnings per share	56,586	52,625	29,831

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Capital Addition Purchase Commitments [Member]
Contingencies And Commitments [Line Items]
Commitments for capital expenditures	$5,717
Investment in Real Estate [Member]
Contingencies And Commitments [Line Items]
Commitments for capital expenditures	$11,479

Gain_on_Involuntary_Conversion1

Gain on Involuntary Conversion - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
Gain On Involuntary Conversion [Abstract]
Proceeds from insurance settlement	$881

Business_Segments_Additional_I

Business Segments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Real_Estate
	Segment
	Sawmills
Segment Reporting [Abstract]
Number of reporting segments	4
Number of business units	3
Number of sawmills	2
Real estate developments	4

Business_Segments_Summary_of_C

Business Segments - Summary of Company's Business Segments (Detail) (USD $)	3 Months Ended												12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net sales
Net sales	$55,070,000	$58,301,000	$58,605,000	$55,379,000	$48,372,000	$56,520,000	$53,247,000	$41,563,000	$36,665,000	$36,499,000	$37,105,000	$30,639,000	$227,355,000	$199,702,000	$140,908,000
Operating income/(loss)
Operating income/(loss)	7,073,000	8,782,000	9,734,000	8,807,000	4,525,000	9,599,000	10,991,000	10,548,000	4,635,000	5,104,000	6,259,000	1,134,000	34,396,000	35,663,000	17,132,000
Equity in earnings of Del-Tin Fiber													0	1,084,000	959,000
Interest income													5,000	13,000	17,000
Interest and other debt expense, net of capitalized interest													-5,430,000	-4,578,000	-4,092,000
Gain on bargain purchase					128,000		3,285,000						0	3,413,000	0
Other income													284,000	3,229,000	20,000
Income before income taxes													29,255,000	38,824,000	14,036,000
Total assets at year-end
Total assets at year-end	527,269,000				411,344,000				353,209,000				527,269,000	411,344,000	353,209,000
Depreciation, amortization, and cost of fee timber harvested
Depreciation, amortization, and cost of fee timber harvested													18,342,000	15,131,000	10,642,000
Capital expenditures
Capital expenditures													20,332,000	24,649,000	9,507,000
Timberland acquisition expenditures													118,203,000	8,919,000	14,527,000
Operating Segments [Member] | Woodlands [Member]
Net sales
Net sales													37,008,000	33,834,000	37,285,000
Operating income/(loss)
Operating income/(loss)													19,113,000	16,749,000	18,374,000
Total assets at year-end
Total assets at year-end	363,436,000				247,156,000				240,026,000				363,436,000	247,156,000	240,026,000
Depreciation, amortization, and cost of fee timber harvested
Depreciation, amortization, and cost of fee timber harvested													5,765,000	4,785,000	4,786,000
Capital expenditures
Capital expenditures													4,038,000	3,836,000	4,026,000
Operating Segments [Member] | Manufacturing [Member]
Net sales
Net sales													189,561,000	167,955,000	105,956,000
Operating income/(loss)
Operating income/(loss)													31,440,000	38,496,000	18,083,000
Total assets at year-end
Total assets at year-end	80,023,000				85,837,000				30,136,000				80,023,000	85,837,000	30,136,000
Depreciation, amortization, and cost of fee timber harvested
Depreciation, amortization, and cost of fee timber harvested													12,147,000	9,910,000	5,378,000
Capital expenditures
Capital expenditures													12,311,000	16,532,000	2,478,000
Operating Segments [Member] | Real Estate [Member]
Net sales
Net sales													16,283,000	11,734,000	10,992,000
Operating income/(loss)
Operating income/(loss)													1,115,000	-1,430,000	-2,099,000
Total assets at year-end
Total assets at year-end	57,646,000				59,549,000				58,783,000				57,646,000	59,549,000	58,783,000
Depreciation, amortization, and cost of fee timber harvested
Depreciation, amortization, and cost of fee timber harvested													355,000	343,000	374,000
Capital expenditures
Capital expenditures													3,934,000	4,267,000	2,996,000
Operating Segments [Member] | Corporate [Member]
Operating income/(loss)
Operating income/(loss)													-17,405,000	-17,994,000	-17,394,000
Total assets at year-end
Total assets at year-end	26,164,000				18,802,000				24,264,000				26,164,000	18,802,000	24,264,000
Depreciation, amortization, and cost of fee timber harvested
Depreciation, amortization, and cost of fee timber harvested													75,000	93,000	104,000
Capital expenditures
Capital expenditures													49,000	14,000	7,000
Eliminations [Member]
Net sales
Net sales													-15,497,000	-13,821,000	-13,325,000
Operating income/(loss)
Operating income/(loss)													$133,000	($158,000)	$168,000

Business_Segments_Summary_of_C1

Business Segments - Summary of Company's Business Segments (Parenthetical) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Segment Reporting [Abstract]
Investment in Del-Tin Fiber			$6,293
Sale proceeds of timberland	$0	$0	$7

Financial_Results_by_Quarter_U2

Financial Results by Quarter (Unaudited) - Quarterly Financial Results (Detail) (USD $)	3 Months Ended												12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data [Abstract]
Net sales	$55,070	$58,301	$58,605	$55,379	$48,372	$56,520	$53,247	$41,563	$36,665	$36,499	$37,105	$30,639	$227,355	$199,702	$140,908
Gross profit	10,447	14,046	14,455	13,930	8,977	14,810	14,648	15,384	9,388	10,237	10,205	5,730	52,878	53,819	35,560
Operating income	7,073	8,782	9,734	8,807	4,525	9,599	10,991	10,548	4,635	5,104	6,259	1,134	34,396	35,663	17,132
Net income	$3,479	$5,974	$5,298	$4,911	$2,337	$5,813	$11,268	$6,774	$2,404	$3,218	$3,516	$97	$19,662	$26,192	$9,235
Earnings per common share
Basic	$0.28	$0.47	$0.42	$0.39	$0.18	$0.46	$0.89	$0.53	$0.19	$0.25	$0.28	$0.01	$1.56	$2.06	$0.73
Assuming dilution	$0.28	$0.47	$0.42	$0.39	$0.18	$0.46	$0.88	$0.53	$0.19	$0.25	$0.28	$0.01	$1.55	$2.05	$0.73
Dividends paid per common share	$0.10	$0.10	$0.10	$0.10	$0.10	$0.10	$0.10	$0.10	$0.08	$0.08	$0.08	$0.08	$0.40	$0.40	$0.30

Financial_Results_by_Quarter_U3

Financial Results by Quarter (Unaudited) - Quarterly Financial Results (Parenthetical) (Detail) (USD $)	3 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data [Abstract]
Gain on bargain purchase	$128	$3,285	$0	$3,413	$0
Gain on previously held equity investment		$3,165	$0	$3,165	$0