SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2016

Real Estate Investment Trust Election (REIT)

OUR ELECTION TO BE TAXED AS A REAL ESTATE INVESTMENT TRUST (REIT)

Starting with our 2010 fiscal year, we elected to be taxed as a REIT. REIT income can be distributed to shareholders without first paying corporate level tax, substantially eliminating the double taxation on income. We expect to derive most of our REIT income from investments in timberlands, including the sale of standing timber through pay-as-cut sales contracts and lump sum timber deeds.

We were no longer subject to the REIT built-in gains tax as of December 31, 2014. Our built-in gains tax period expired in 2015 due to a change in U.S. tax law that statutorily shortened the built-in gains tax period to 5 years from 10 years. This means we are no longer subject to federal corporate level income taxes on sales of REIT property that had a fair market value in excess of tax basis when we converted to a REIT on January 1, 2010. We continue to be required to pay federal corporate income taxes on earnings of our Taxable REIT Subsidiary (TRS), which includes our Wood Products segment and portions of our Timberlands and Real Estate, Energy and Natural Resources (Real Estate & ENR) segments.

Consolidated Financial Statements

CONSOLIDATED FINANCIAL STATEMENTS

Our consolidated financial statements provide an overall view of our results and financial condition. They include our accounts and the accounts of entities that we control, including:


•	majority-owned domestic and foreign subsidiaries and


•	variable interest entities in which we are the primary beneficiary.

They do not include our intercompany transactions and accounts, which are eliminated, and noncontrolling interests are presented as a separate component of equity.

We account for investments in and advances to unconsolidated equity affiliates using the equity method. We record our share of equity in net earnings of equity affiliates within "Equity earnings from joint ventures" in our Consolidated Statement of Operations in the period in which the earnings are recorded by our equity affiliates.

Our Business Segments

OUR BUSINESS SEGMENTS

Reportable business segments are determined based on the company's management approach. The management approach, as defined by FASB ASC 280, "Segment Reporting," is based on the way the chief operating decision maker organizes the segments within a company when making decisions about resources to be allocated and assessing their performance.

During fiscal year 2016, the company's chief operating decision maker changed the information regularly reviewed when making decisions to allocate resources and assess performance. As a result, the company will report its financial performance based on three business segments: Timberlands, Real Estate & ENR, and Wood Products. Prior to revising our segment structure, activities related to the Real Estate & ENR business segment were reported as part of the Timberlands business segment.

Amounts for all periods presented have been reclassified throughout the consolidated financial statements and disclosures to conform to the new segment structure.

We are principally engaged in:


•	growing and harvesting timber;


•	manufacturing, distributing and selling products made from trees;


•	maximizing the value of every acre we own through the sale of higher and better use (HBU) properties; and


•	monetizing reserves of minerals, oil, gas, coal, and other natural resources on our timberlands.

Our business segments are organized based primarily on products and services.

Our Business Segments and Products



SEGMENT	PRODUCTS AND SERVICES
Timberlands	Logs, timber, and recreational access via leases
Real Estate & ENR	Sales of timberlands; rights to explore for and extract hard minerals, oil and gas production, and coal; and equity interests in our Real Estate Development Ventures
Wood Products	Softwood lumber, engineered wood products, structural panels, medium density fiberboard and building materials distribution

We also transfer raw materials, semifinished materials and end products among our business segments. Because of this intracompany activity, accounting for our business segments involves:


•	pricing products transferred between our business segments at current market values and


•	allocating joint conversion and common facility costs according to usage by our business segment product lines.

Gains or charges not related to or allocated to an individual operating segment are held in Unallocated Items. This includes a portion of items such as: share-based compensation; pension and postretirement costs; foreign exchange transaction gains and losses associated with financing; the elimination of intersegment profit in inventory and the LIFO reserve.

Foreign Currency Translation

FOREIGN CURRENCY TRANSLATION

Local currencies are the functional currencies for most of our operations outside the U.S. We translate foreign currencies into U.S. dollars in two ways:


•	assets and liabilities — at the exchange rates in effect as of our balance sheet date; and


•	revenues and expenses — at average monthly exchange rates throughout the year.

Estimates

ESTIMATES

We prepare our financial statements according to U.S. generally accepted accounting principles (U.S. GAAP). This requires us to make estimates and assumptions during our reporting periods and at the date of our financial statements. The estimates and assumptions affect our:


•	reported amounts of assets, liabilities and equity;


•	disclosure of contingent assets and liabilities; and


•	reported amounts of revenues and expenses.

While we do our best in preparing these estimates, actual results can and do differ from those estimates and assumptions.

Fair Value Measurements

FAIR VALUE MEASUREMENTS

We use a fair value hierarchy in accounting for certain nonfinancial assets and liabilities including:


•	long-lived assets (asset groups) measured at fair value for an impairment assessment;


•	reporting units measured at fair value in the first step of a goodwill impairment test;


•	nonfinancial assets and nonfinancial liabilities measured at fair value in the second step of a goodwill impairment assessment;


•	assets acquired and liabilities assumed in a business acquisition; and


•	asset retirement obligations initially measured at fair value.

The fair value hierarchy is based on inputs to valuation techniques that are used to measure fair value that are either observable or unobservable. Observable inputs reflect assumptions market participants would use in pricing an asset or liability based on market data obtained from independent sources while unobservable inputs reflect a reporting entity’s pricing based upon its own market assumptions.

The fair value hierarchy consists of the following three levels:


•	Level 1 — Inputs are quoted prices in active markets for identical assets or liabilities.


•	Level 2 — Inputs are:

– quoted prices for similar assets or liabilities in an active market;

– quoted prices for identical or similar assets or liabilities in markets that are not active; or

– inputs other than quoted prices that are observable and market-corroborated inputs, which are derived principally from or corroborated by observable market data.


•	Level 3 — Inputs are derived from valuation techniques in which one or more significant inputs or value drivers are unobservable.

Reclassifications

RECLASSIFICATIONS

We have reclassified certain balances and results from the prior years to be consistent with our 2016 reporting. This makes year-to-year comparisons easier. Our reclassifications had no effect on net earnings or equity.

Our reclassifications present:


•	our adoption of new accounting pronouncements.


•	the results of discontinued operations separately from results of continuing operations on our Consolidated Statement of Operations, Consolidated Balance Sheet and in the related footnotes. Note 3: Discontinued Operations provides more information about our discontinued operations.


•	our revised business segments. Note 2: Business Segments provides information about our revised business segments.

New Accounting Pronouncements

NEW ACCOUNTING PRONOUNCEMENTS

In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-09, a comprehensive new revenue recognition model that requires an entity to recognize revenue to depict the transfer of goods or services to customers at an amount that reflects the consideration it expects to receive in exchange for those goods or services. In August 2015, FASB issued ASU 2015-14, which deferred the effective date for an additional year. In March 2016, FASB issued ASU 2016-08, which does not change the core principle of the guidance; however, it does clarify the implementation guidance on principal versus agent considerations. In April 2016, FASB issued ASU 2016-10, which clarifies two aspects of ASU 2014-09: identifying performance obligations and the licensing implementation guidance. In May 2016, FASB issued ASU 2016-12, which amends ASU 2014-09 to provide improvements and practical expedients to the new revenue recognition model. Finally, in December 2016, the FASB issued ASU 2016-20, which amends ASU 2014-09 for technical corrections and to correct for unintended application of the guidance.

The company expects to adopt and implement the new revenue recognition guidance effective January 1, 2018. The new standard is required to be applied retrospectively to each prior reporting period presented (full retrospective transition method) or retrospectively with the cumulative effect of initially applying it recognized at the date of initial application (cumulative effect method). We expect to adopt using the cumulative effect method. We expect that the adoption of the new revenue recognition guidance will not materially impact our operating results, balance sheet, cash flows or financial reporting aside from adding expanded disclosures.

In April 2015, FASB issued ASU 2015-03, which amends the presentation of debt issuance costs on the consolidated balance sheet. Under the new guidance, debt issuance costs are presented as a direct deduction from the carrying amount of the debt liability rather than as an asset. The new guidance is effective retrospectively for fiscal periods starting after December 15, 2015 and early adoption is permitted. We adopted on January 1, 2016, and have reclassified balances of debt issuance costs accordingly in our consolidated balance sheet and in related disclosures for all periods presented.

In May 2015, FASB issued ASU 2015-07, which clarifies the presentation within the fair value hierarchy of certain investments held within our pension plan. The new guidance is effective retrospectively for fiscal periods starting after December 15, 2015. This new guidance removes the requirement to categorize within the fair value hierarchy investments for which fair value is measured using the net asset value per share as a practical expedient and, instead, permits separate disclosure. Upon adoption these investments are presented separately from the fair value hierarchy and reconciled to total investments in our consolidated financial statements and related disclosures. We adopted on January 1, 2016. We have included all new required disclosures in Note 9: Pension and Other Postretirement Benefit Plans.

In July 2015, FASB issued ASU 2015-11, which simplifies the measurement of inventories valued under most methods, including our inventories valued under FIFO – the first-in, first-out – and moving average cost methods. Inventories valued under LIFO – the last-in, first-out method – are excluded. Under this new guidance, inventories valued under these methods would be valued at the lower of cost or net realizable value, with net realizable value defined as the estimated selling price less reasonable costs to sell the inventory. The new guidance is effective prospectively for fiscal periods starting after December 15, 2016, and early adoption is permitted. We adopted on January 1, 2017, and determined this pronouncement does not have a material impact on our consolidated financial statements and related disclosures.

In September 2015, FASB issued ASU 2015-16, which results in the ability to recognize, in current period earnings, any changes in provisional amounts during the measurement period after the closing of an acquisition, instead of restating prior periods for these changes. We adopted on January 1, 2016. Measurement period adjustments related to our merger with Plum Creek did not have a material impact to earnings or cash flows for the year ended December 31, 2016.

In February 2016, FASB issued ASU 2016-02, which requires lessees to recognize assets and liabilities for the rights and obligations created by those leases and requires both capital and operating leases to be recognized on the balance sheet. The new guidance is effective for fiscal years beginning after December 15, 2018, and early adoption is permitted. We expect to adopt on January 1, 2019, and are evaluating the impact on our consolidated financial statements and related disclosures.

In March 2016, FASB issued ASU 2016-09, which simplifies several aspects of accounting for share-based payment transactions, including income tax consequences, award classification, cash flows reporting, and forfeiture rate application. Specifically, the update requires all excess tax benefits and tax deficiencies to be recognized as income tax expense or benefit in the income statement with a cumulative-effect adjustment to equity as of the beginning of the period of adoption. The update allows excess tax benefits to be classified along with other income tax cash flows as an operating activity on the statement of cash flows. When accruing compensation cost, an entity can make an entity-wide accounting policy election to either estimate the number of awards expected to vest or to account for forfeitures as they occur with a cumulative-effect adjustment to equity as of the beginning of the period of adoption. The update requires cash paid by an employer when directly withholding shares for tax-withholding purposes to be classified as a financing activity on the statement of cash flows, applied retrospectively. This guidance is effective for fiscal years beginning after December 15, 2016. As permitted, we elected to adopt early, and applied the different aspects as prescribed by the standard effective January 1, 2016. The adoption of this guidance represents a change in accounting policy and did not have a material impact on our consolidated financial statements. Shares withheld by the employer for tax-withholding purposes for the years ended December 31, 2015, and December 31, 2014, of $11 million and $21 million, respectively, were retrospectively reclassified from an operating activity to a financing activity in the Consolidated Statement of Cash Flows.

In August 2016, FASB issued ASU 2016-15, which reduces diversity in practice in how certain transactions are classified in the statement of cash flows. These transactions include: debt prepayment or debt extinguishment costs, settlement of zero-coupon debt instruments, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies, distributions received from equity method investments, beneficial interests in securitization transactions, and separately identifiable cash flows and application of the predominance principle. The new guidance is effective for fiscal years beginning after December 15, 2017, and early adoption is permitted. We have adopted this update effective July 1, 2016, and our adoption did not materially impact our Consolidated Statement of Cash Flows.

In October 2016, FASB issued ASU 2016-16, which requires immediate recognition of the income tax consequences upon intra-entity transfers of assets other than inventory. The new guidance is effective for annual periods beginning after December 15, 2017, and early adoption is permitted. We adopted this accounting standard update on January 1, 2017, which does not materially impact our consolidated financial statements or related disclosures. In general, we do not have material intra-entity taxable sales of assets other than inventory.

Property and Equipment

We maintain property accounts on an individual asset basis. Here is how we handle major items:


•	Improvements to and replacements of major units of property are capitalized.


•	Maintenance, repairs and minor replacements are expensed.


•	Depreciation is calculated using a straight-line method at rates based on estimated service lives.


•	Logging roads are generally amortized — as timber is harvested — at rates based on the volume of timber estimated to be removed.


•	Cost and accumulated depreciation of property sold or retired are removed from the accounts and the gain or loss is included in earnings.

In general, additions are classified into components, each with its own estimated useful life as determined at the time of purchase.

Timber and Timberlands

We carry timber and timberlands at cost less depletion charged to disposals. Depletion refers to the carrying value of timber that is harvested, lost as a result of casualty, or sold.

Key activities affecting how we account for timber and timberlands include:


•	reforestation,


•	depletion and


•	forest management in Canada.

Reforestation. Generally, we capitalize initial site preparation and planting costs as reforestation. We transfer reforestation to a merchantable timber classification when the timber is considered harvestable. This generally occurs after:


•	15 years in the South and


•	30 years in the West.

Generally, we expense costs after the first planting as they are incurred or over the period of expected benefit. These costs include:


•	fertilization,


•	vegetation and insect control,


•	pruning and precommercial thinning,


•	property taxes and


•	interest.

Accounting practices for these costs do not change when timber becomes merchantable and harvesting starts.

Timber depletion. To determine depletion rates, we divide the net carrying value of timber by the related volume of timber estimated to be available over the growth cycle. To determine the growth cycle volume of timber, we consider:


•	regulatory and environmental constraints,


•	our management strategies,


•	inventory data improvements,


•	growth rate revisions and recalibrations and


•	known dispositions and inoperable acres.

We include the cost of timber harvested in the carrying values of raw materials and product inventories. As these inventories are sold to third parties, we include them in the cost of products sold.

Forest management in Canada. We manage timberlands under long-term licenses in various Canadian provinces that are:


•	granted by the provincial governments;


•	granted for initial periods of 15 to 25 years; and


•	renewable provided we meet reforestation, operating and management guidelines.

Calculation of the fees we pay on the timber we harvest:


•	varies from province to province,


•	is tied to product market pricing and


•	depends upon the allocation of land management responsibilities in the license.

Impairment of Long-Lived Assets

We review long-lived assets — including certain identifiable intangibles — for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. Impaired assets held for use are written down to fair value. Impaired assets held for sale are written down to fair value less cost to sell. We determine fair value based on:


•	appraisals,


•	market pricing of comparable assets,


•	discounted value of estimated cash flows from the asset and


•	replacement values of comparable assets.

Goodwill

Goodwill is the purchase price minus the fair value of net assets acquired when we buy another entity. We assess goodwill for impairment:


•	using a fair-value-based approach and


•	at least annually — at the beginning of the fourth quarter.

In 2016, the fair value of the reporting unit with goodwill substantially exceeded its carrying value.

Financial Instruments

We estimate the fair value of financial instruments where appropriate. The assumptions we use — including the discount rate and estimates of cash flows — can significantly affect our fair-value amounts. Our fair values are estimates and may not match the amounts we would realize upon sale or settlement of our financial positions.

To estimate the fair value of long-term debt, we used the following valuation approaches:


•	market approach — based on quoted market prices we received for the same types and issues of our debt; or


•	income approach — based on the discounted value of the future cash flows using market yields for the same type and comparable issues of debt.

We believe that our variable rate long-term debt instruments have net carrying values that approximate their fair values with only insignificant differences.

The inputs to these valuations are based on market data obtained from independent sources or information derived principally from observable market data. The difference between the fair value and the carrying value represents the theoretical net premium or discount we would pay or receive to retire all debt at the measurement date.

FAIR VALUE OF OTHER FINANCIAL INSTRUMENTS

We believe that our other financial instruments, including cash and cash equivalents, short-term investments, mutual fund investments held in grantor trusts, receivables, and payables, have net carrying values that approximate their fair values with only insignificant differences. This is primarily due to the short term nature of these instruments and the allowance for doubtful accounts.

Cash and Cash Equivalents and Accounts Payable

Cash Equivalents

Cash equivalents are investments with original maturities of 90 days or less. We state cash equivalents at cost, which approximates market.

Accounts Payable

Our banking system replenishes our major bank accounts daily as checks we have issued are presented for payment. As a result, we have negative book cash balances due to outstanding checks that have not yet been paid by the bank. These negative balances are included in "Accounts payable" on our Consolidated Balance Sheet. Changes in these negative cash balances are reported as financing activities in our Consolidated Statement of Cash Flows. We had no negative book cash balances as of December 31, 2016 and December 31, 2015.

Concentration of Risk

We disclose customers that represent a concentration of credit risk. As of December 31, 2016 and December 31, 2015, no customer accounted for 10 percent or more of our net sales

Revenue Recognition

Operations generally recognize revenue upon shipment to customers. For certain export sales, revenue is recognized when title transfers at the foreign port.

For timberland sales, we recognize revenue when title and possession have been transferred to the buyer and all other criteria for sale and profit recognition have been satisfied.

Inventories

We state inventories at the lower of cost or market. Cost includes labor, materials and production overhead. LIFO — the last-in, first-out method — applies to major inventory products held at our U.S. domestic locations. We began to use the LIFO method for domestic products in the 1940s as required to conform with the tax method elected. Subsequent acquisitions of entities added new products under the FIFO — the first-in, first-out method — or moving average cost methods that have continued under those methods. The FIFO or moving average cost methods applies to the balance of our domestic raw material and product inventories as well as for all material and supply inventories and all foreign inventories.

Shipping and Handling Costs

We classify shipping and handling costs in "Costs of products sold" on our Consolidated Statement of Operations.

Income Taxes

We account for income taxes under the asset and liability method. Unrecognized tax benefits represent potential future funding obligations to taxing authorities if uncertain tax positions the company has taken on previously filed tax returns are not sustained. In accordance with the company’s accounting policy, accrued interest and penalties related to unrecognized tax benefits are recognized as a component of income tax expense.

We recognize deferred tax assets and liabilities to reflect:


•	future tax consequences due to differences between the carrying amounts for financial purposes and the tax bases of certain items and


•	operating loss and tax credit carryforwards.

To measure deferred tax assets and liabilities, we:


•	determine when the differences between the carrying amounts and tax bases of affected items are expected to be recovered or resolved and


•	use enacted tax rates expected to apply to taxable income in those years.

Share-Based Compensation

We generally measure the fair value of share-based awards on the dates they are granted or modified. These measurements establish the cost of the share-based awards for accounting purposes. We then recognize the cost of share-based awards in our Consolidated Statement of Operations over each employee’s required service period. Note 16: Share-Based Compensation provides more information about our share-based compensation.

HOW WE ACCOUNT FOR SHARE-BASED AWARDS

When accounting for share-based awards we:


•	use a fair-value-based measurement for share-based awards and


•	recognize the cost of share-based awards in our consolidated financial statements.

We recognize the cost of share-based awards in our Consolidated Statement of Operations over the required service period — generally the period from the date of the grant to the date when it is vested. Special situations include:


•	Awards that vest upon retirement — the required service period ends on the date an employee is eligible for retirement, including early retirement.


•	Awards that continue to vest following job elimination or the sale of a business — the required service period ends on the date the employment from the company is terminated.

In these special situations, compensation expense from share-based awards is recognized over a period that is shorter than the stated vesting period.

Pension and Other Postretirement Benefit Plans

We recognize the overfunded or underfunded status of our defined benefit pension and other postretirement plans on our Consolidated Balance Sheet and recognize changes in the funded status through comprehensive income (loss) in the year in which the changes occur.

Actuarial valuations determine the amount of the pension and other postretirement benefit obligations and the net periodic benefit cost we recognize. The net periodic benefit cost includes:


•	cost of benefits provided in exchange for employees’ services rendered during the year;


•	interest cost of the obligations;


•	expected long-term return on plan assets;


•	gains or losses on plan settlements and curtailments;


•	amortization of prior service costs and plan amendments over the average remaining service period of the active employee group covered by the plans or the average remaining life expectancy in situations where the plan participants affected by the plan amendment are inactive; and

•

amortization of cumulative unrecognized net actuarial gains and losses — generally in excess of 10 percent of the greater of the benefit obligation or market-related value of plan assets at the beginning of the year — over the average remaining service period of the active employee group covered by the plans or the average remaining life expectancy in situations where the plan participants are inactive.

Pension plans. We have pension plans covering most of our employees. Determination of benefits differs for salaried, hourly and union employees:


•	Salaried employee benefits are based on each employee’s highest monthly earnings for five consecutive years during the final 10 years before retirement.


•	Hourly and union employee benefits generally are stated amounts for each year of service.


•	Union employee benefits are set through collective-bargaining agreements.

We contribute to our U.S. and Canadian pension plans according to established funding standards. The funding standards for the plans are:


•	U.S. pension plans — according to the Employee Retirement Income Security Act of 1974; and


•	Canadian pension plans — according to the applicable provincial pension act and the Income Tax Act.

Postretirement benefits other than pensions. We provide certain postretirement health care and life insurance benefits for some retired employees. In some cases, we pay a portion of the cost of the benefit. Note 9: Pension and Other Postretirement Benefit Plans provides additional information about changes made in our postretirement benefit plans during 2016 and 2015.

The pension assets are stated at fair value based upon the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the reporting date. We do not value pension investments based upon a forced or distressed sale scenario. Instead, we consider both observable and unobservable inputs that reflect assumptions applied by market participants when setting the exit price of an asset or liability in an orderly transaction within the principal market of that asset or liability.

We value the pension plan assets based upon the observability of exit pricing inputs and classify pension plan assets based upon the lowest level input that is significant to the fair value measurement of the pension plan assets in their entirety. The fair value hierarchy we follow is outlined below;

Level 1: Inputs are unadjusted quoted prices for identical assets and liabilities traded in an active market.

Level 2: Inputs are quoted prices in non-active markets for which pricing inputs are observable either directly or indirectly at the reporting date.

Level 3: Inputs are derived from valuation techniques in which one or more significant inputs or value drivers are unobservable.

The pension assets are comprised of cash and short-term investments, derivative investments, common and preferred stock and fund units. The fund units are typically limited liability interests in hedge funds, private equity and related investments. Each of these assets participates in its own unique principal market.

Cash and short-term investments when held directly are valued at cost, which approximates market.

Common and preferred stocks are valued at exit prices quoted in the public markets.

Fund units are valued based upon the net asset values of the funds which we believe represent the per-unit prices at which new investors are permitted to invest and the prices at which existing investors are permitted to exit. To the degree net asset values as of the end of the year have not been received, we use the most recently reported net asset values and adjust for market events and cash flows that have occurred between the interim date and the end of the year to estimate the fair values as of the end of the year.

Derivative instruments held by our pension trusts are not publicly traded and each derivative contract is specifically negotiated with a unique financial counterparty and references either illiquid fund units or a unique number of synthetic units of a publicly reported market index. The derivative contracts are valued based upon valuation statements received from the financial counterparties.

Assets that do not have readily available quoted prices in an active market require a higher degree of judgment to value and have a higher degree of risk that the value that could have been realized upon sale as of the valuation date could be different from the reported value than assets with observable pricing inputs. It is possible that the full extent of market price, liquidity, currency, interest rate, or credit risks may not be fully factored into the fair values of our pension plan assets that use significant unobservable inputs.

We estimate the fair value of pension plan assets based upon the information available during the year-end reporting process. In some cases, primarily private equity funds, the information available consists of net asset values as of an interim date, cash flows between the interim date and the end of the year, and market events. When the difference is significant, we revise the year-end estimated fair value of pension plan assets to incorporate year-end net asset values received after we have filed our annual report on Form 10-K.

Environmental Remediation

We accrue losses associated with environmental remediation obligations when such losses are probable and reasonably estimable. Future expenditures for environmental remediation obligations are not discounted to their present value. Recoveries of environmental remediation costs from other parties are recorded as assets when the recovery is deemed probable and does not exceed the amount of losses previously recorded.

Estimates. We believe it is reasonably possible, based on currently available information and analysis, that remediation costs for all identified sites may exceed our existing reserves by up to $110 million.

This estimate, in which those additional costs may be incurred over several years, is the upper end of the range of reasonably possible additional costs. The estimate:


•	is much less certain than the estimates on which our accruals currently are based and


•	uses assumptions that are less favorable to us among the range of reasonably possible outcomes.

In estimating our current accruals and the possible range of additional future costs, we:


•	assumed we will not bear the entire cost of remediation of every site,


•	took into account the ability of other potentially responsible parties to participate and


•	considered each party’s financial condition and probable contribution on a per-site basis.

Merger

Weyerhaeuser has accounted for the merger transaction as the acquirer and has applied the acquisition method of accounting. Under the acquisition method, the assets acquired and liabilities assumed by Weyerhaeuser from Plum Creek were recorded as of the date of the acquisition at their respective estimated fair values.

The fair values of the assets acquired and liabilities assumed were determined using the income, cost or market approaches. The fair value measurements were generally based on significant inputs that are not observable in the market and thus represent Level 3 measurements as defined in ASC 820, Fair Value Measurement, with the exception of certain long-term debt instruments assumed in the acquisition that were valued using observable market inputs and are therefore Level 2 measurements. The income approach was primarily used to value acquired timberlands, minerals and mineral rights, equity investments in the Timberland Venture (as defined and described in Note 8: Related Parties) and Real Estate Development Ventures (as defined and described in Note 8: Related Parties), and the Note Payable to Timberland Venture (as defined and described in Note 12: Long-term Debt). The income approach estimates fair value for an asset based on the present value of cash flow projected to be generated by the asset. Projected cash flows are discounted at rates of return that reflect the relative risk of achieving the cash flows and the time value of money. The cost approach, which estimates value by determining the current cost of replacing an asset with another of equivalent economic utility, was used, as appropriate, for property and equipment. The cost to replace a given asset reflects the estimated reproduction or replacement cost for the property, less an allowance for loss in value due to depreciation. The market approach was primarily used to value higher and better use real estate tracts included within acquired timberlands, certain land and building assets included within acquired property and equipment, and long-term debt instruments. The market approach estimates fair value for an asset based on values of recent comparable transactions.

Earnings Per Share

"Basic earnings" per share is net earnings available to common shareholders divided by the weighted average number of our outstanding common shares, including stock equivalent units where there is no circumstance under which those shares would not be issued.

"Diluted earnings" per share is net earnings available to common shareholders divided by the sum of the:


•	weighted average number of our outstanding common shares and


•	the effect of our outstanding dilutive potential common shares.

Dilutive potential common shares may include:


•	outstanding stock options,


•	restricted stock units,


•	performance share units and


•	preference shares.

We use the treasury stock method to calculate the dilutive effect of our outstanding stock options, restricted stock units and performance share units. Share-based payment awards that are contingently issuable upon the achievement of specified performance or market conditions are included in our diluted earnings per share calculation in the period in which the conditions are satisfied.

Stock Repurchase Programs Policy

All common stock purchases under the 2016, 2015, and 2014 Repurchase Programs were made in open-market transactions.

We record share repurchases upon trade date as opposed to the settlement date when cash is disbursed. We record a liability to account for repurchases that have not been cash settled.