Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2018
Accounting Policies [Abstract]
Use of Estimates [Policy Text Block]	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires management to make estimates and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenues and expenses. Such estimates include the valuation of accounts receivable, inventories, goodwill, intangible assets, and other long-lived assets; legal contingencies; guarantee obligations; indemnifications; assumptions used in retirement, medical, and workers' compensation benefits; stock-based compensation; fair value measurements; income taxes; and vendor and customer rebates, among others. These estimates and assumptions are based on management's best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. We adjust such estimates and assumptions when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in these estimates resulting from continuing changes in the economic environment will be reflected in the consolidated financial statements in future periods.
Vendor Rebates and Allowances [Policy Text Block]	Rebates and allowances received from our vendors are recognized as a reduction of "Materials, labor, and other operating expenses (excluding depreciation)" when the product is sold, unless the rebates and allowances are linked to a specific incremental cost to sell a vendor's product. Amounts received from vendors that are linked to specific selling and distribution expenses are recognized as a reduction of "Selling and distribution expenses" in the period the expense is incurred.
Lessee, Leases [Policy Text Block]	For purposes of determining straight-line rent expense, the lease term is calculated from the date we first take possession of the facility, including any periods of free rent and any renewal option periods we are reasonably assured of exercising.
Fair Value [Policy Text Block]	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy under GAAP gives the highest priority to quoted market prices (Level 1) and the lowest priority to unobservable inputs (Level 3). In general, and where applicable, we use quoted prices in active markets for identical assets or liabilities to determine fair value (Level 1). If quoted prices in active markets for identical assets or liabilities are not available to determine fair value, we use quoted prices for similar assets and liabilities or inputs that are observable either directly or indirectly (Level 2). If quoted prices for identical or similar assets are not available or are unobservable, we may use internally developed valuation models, whose inputs include bid prices, and third-party valuations utilizing underlying asset assumptions (Level 3).
Financial Instruments [Policy Text Block]	Our financial instruments are cash and cash equivalents, accounts receivable, accounts payable, long-term debt, and interest rate swaps. Our cash is recorded at cost, which approximates fair value, and our cash equivalents are money market funds. As of March 31, 2018, and December 31, 2017, we held $55.8 million and $137.5 million, respectively, in money market funds that are measured at fair value on a recurring basis using Level 1 inputs. The recorded values of accounts receivable and accounts payable approximate fair values based on their short-term nature. At March 31, 2018, and December 31, 2017, the book value of our fixed-rate debt for each period was $350.0 million, and the fair value was estimated to be $358.8 million and $369.3 million, respectively. The difference between the book value and the fair value is derived from the difference between the period-end market interest rate and the stated rate of our fixed-rate, long-term debt. We estimated the fair value of our fixed-rate debt using quoted market prices of our debt in inactive markets (Level 2 inputs). The interest rate on our term loans is based on market conditions such as the London Interbank Offered Rate (LIBOR) or a base rate. Because the interest rate on the term loans is based on current market conditions, we believe that the estimated fair value of the outstanding balance on our term loans approximates book value. As discussed below, we also have interest rate swaps to mitigate our variable interest rate exposure, the fair value of which is measured based on Level 2 inputs.
Derivatives [Policy Text Block]	In accordance with our risk management strategy, we actively monitor our interest rate exposure and use derivative instruments from time to time to manage the related risk.
New and recently adopted accounting standards [Policy Text Block]	In March 2018, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2018-05, Income Taxes (Topic 740), Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118. The amendments in this ASU add various Securities and Exchange Commission (SEC) paragraphs pursuant to the issuance of SEC Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (Tax Act) (SAB 118). The SEC issued SAB 118 to address concerns about reporting entities' ability to timely comply with the accounting requirements to recognize all of the effects of the Tax Act in the period of enactment. SAB 118 allows disclosure that timely determination of some or all of the income tax effects from the Tax Act are incomplete by the due date of the financial statements and, if possible, to provide a reasonable estimate. See Note 4, Income Taxes, for our assessment of the income tax effects of the Tax Act. In February 2018, the FASB issued ASU 2018-02, Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This ASU permits entities to reclassify stranded tax effects in accumulated other comprehensive income to retained earnings as a result of the Tax Cuts and Jobs Act enacted by the U.S. federal government on December 22, 2017. The updated guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted. We are currently evaluating the effects of this ASU on our financial statements. In March 2017, the FASB issued ASU 2017-07, Compensation—Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. This ASU requires entities to present the service cost component of net periodic benefit cost in the same income statement line item(s) as other employee compensation costs arising from services rendered during the period. The other components of net periodic benefit cost must be presented elsewhere in the income statement and outside of income from operations if that subtotal is presented. Entities will have to disclose the line(s) used to present the other components of net periodic benefit cost if the components are not presented separately in the income statement. The guidance on the income statement presentation of the components of net periodic benefit cost must be applied retrospectively. We adopted the standard in first quarter 2018, which resulted in a change in our income from operations in an amount equal to the other components of net periodic pension cost, which was offset by a corresponding change outside of income from operations. The amount recorded outside of income from operations is presented in "Pension expense (excluding service costs)" in our Consolidated Statements of Operations. The components of net periodic cost are shown in Note 7, Retirement and Benefit Plans. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This amendment requires a lessee to recognize substantially all leases (whether operating or finance leases) on the balance sheet as a right-of-use asset and an associated lease liability. Short-term leases of 12 months or less are excluded from this amendment. For leases defined as finance leases under the new standard, the lessee subsequently recognizes interest expense and amortization of the right-of-use asset, similar to accounting for capital leases under current GAAP. For leases defined as operating leases under the new standard, the lessee subsequently recognizes straight-line lease expense over the life of the lease. This new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The guidance is to be applied using a modified retrospective transition method with the option to elect a package of practical expedients. The adoption of this ASU will result in a significant increase to our balance sheet for lease liabilities and right-of-use assets, which has not yet been quantified. We are currently evaluating this and the other effects of this ASU on our financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). This ASU replaced most existing revenue recognition guidance in U.S. GAAP when it became effective and requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The guidance also requires additional disclosure to help users of financial statements better understand the nature, amount, timing, and uncertainty of revenue that is recognized. We adopted this standard effective January 1, 2018. See Note 3, Revenues, for the impact of this standard on our revenue recognition practices and additional required qualitative disclosures of our revenue recognition policies.
Revenue Recognition [Policy Text Block]	Revenue Recognition Revenues are recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. For revenue disaggregated by major product line for each reportable segment, see Note 11, Segment Information. Wood Products Segment Our Wood Products segment manufactures EWP, consisting of laminated veneer lumber (LVL), I-joists, and laminated beams, which are structural products used in applications where extra strength and consistent quality are required, such as headers and beams. LVL is also used in the manufacture of I-joists, which are assembled by combining a vertical web of oriented strand board (OSB) with top and bottom LVL or solid wood flanges. In addition, we manufacture structural, appearance, and industrial plywood panels. We also produce ponderosa pine lumber, studs, and particleboard. Our wood products are used primarily in new residential construction, residential repair-and-remodeling markets, and light commercial construction. The majority of our wood products are sold to leading wholesalers (including our Building Materials Distribution segment), home improvement centers, retail lumberyards, and industrial converters. For engineered wood products (EWP), plywood and veneer, lumber, byproducts, particleboard, and other products, we transfer control and recognize a sale when we ship the product from our manufacturing facility to our customer. Control transfers when product is shipped because the customer has legal title, a present obligation to pay, and risk and rewards of ownership. The amount of consideration we receive and revenue we recognize varies with changes in rebates and cash discounts we offer to our customers. See discussion of rebates and cash discounts below. Building Materials Distribution Segment Our Building Materials Distribution segment is a leading national stocking wholesale distributor of building materials. We distribute a broad line of building materials, including EWP; commodity products such as OSB, plywood, and lumber; and general line items such as siding, metal products, insulation, roofing, and composite decking. Except for EWP, we purchase most of these building materials from third-party suppliers and market them primarily to retail lumberyards, home improvement centers, and specialty distributors that then sell the products to the final end customers, who are typically professional builders, independent contractors, and homeowners engaged in residential construction projects. Substantially all of Building Materials Distribution's EWP is sourced from our Wood Products segment. We sell products using two primary distribution methods: warehouse sales and direct sales. Warehouse sales are distributed from our warehouses to our customers. Direct sales are shipped from the manufacturer to the customer without our taking physical inventory possession. We report direct sales on a gross basis, that is, the amounts billed to our customers are recorded as "Sales," and inventory purchased from manufacturers are recorded as "Materials, labor, and other operating expenses (excluding depreciation)." We are the principal of direct sales because we control the inventory before it is transferred to our customers. Our control is evidenced by us being primarily responsible for fulfilling the promise to our customers, taking on inventory risk of returned product, and having discretion in establishing pricing. For warehouse sales, we transfer control and recognize a sale when the customer takes physical possession of the product. Control transfers when the customer takes physical possession of the product because the customer has legal title, a present obligation to pay, and risk and rewards of ownership. For direct sales, we transfer control and recognize a sale when the product is shipped from the manufacturer to the customer. Control transfers when product is shipped because the customer has legal title, a present obligation to pay, and risk and rewards of ownership. The amount of consideration we receive and revenue we recognize varies with changes in customer rebates and cash discounts we offer to our customers. See discussion of rebates and cash discounts below. Rebates and Cash Discounts Rebates are provided to our customers and our customers' customers based on the volume of their purchases, among other factors such as customer loyalty, conversion, and commitment. We provide the rebates to increase the sell-through of our products. Rebates are generally estimated based on the expected amount to be paid and recorded as a decrease in "Sales." At March 31, 2018, and December 31, 2017, we had $46.8 million and $45.5 million, respectively, of rebates payable to our customers recorded in "Accrued liabilities, Other" on our Consolidated Balance Sheets. We estimate the expected cash discounts based on an analysis of historical experience and record cash discounts as a decrease in "Sales." We adjust our estimate of revenue at the earlier of when the probability of rebates paid and cash discounts provided changes or when the amounts become fixed. We believe that there will not be significant changes to our estimates of variable consideration. Shipping and Handling Fees for shipping and handling charged to customers for sales transactions are included in "Sales." When control over products has transferred to the customer, we have elected to recognize costs related to shipping and handling as an expense. For our Wood Products segment, costs related to shipping and handling are included in "Materials, labor, and other operating expenses (excluding depreciation)." In our Wood Products segment, we view our shipping and handling costs as a cost of the manufacturing process and the movement of product to our end customers. For our Building Materials Distribution segment, costs related to shipping and handling of $33.6 million and $29.3 million, respectively, are included in "Selling and distribution expenses" for the three months ended March 31, 2018, and 2017. In our Building Materials Distribution segment, our activities relate to the purchase and resale of finished product, and excluding shipping and handling costs from “Materials, labor, and other operating expenses (excluding depreciation)” provides us a clearer view of our operating performance and the effectiveness of our sales and purchasing functions. Other Our payment terms vary by the type of customer and the products offered. The term between invoicing and when payment is due is not significant.
Revenue, Transaction Price Measurement, Tax Exclusion [Policy Text Block]	Sales, value add, and other taxes we collect concurrent with revenue-producing activities are excluded from revenue.
Commissions Expense [Policy Text Block]	We expense sales commissions when incurred as they are earned when the product is shipped. These costs are recorded within "Selling and distribution expenses."
Compensation Related Costs [Policy Text Block]	We record compensation expense over the awards' vesting period and account for share-based award forfeitures as they occur, rather than making estimates of future forfeitures. Any shares not vested are forfeited. We recognize stock awards with only service conditions on a straight-line basis over the requisite service period.