Weyerhaeuser (WY) 10-K 15 Feb 19 2018 FY Annual report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2018	Feb. 04, 2019	Jun. 30, 2018
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Entity Registrant Name	WEYERHAEUSER CO
Trading Symbol	WY
Entity Central Index Key	106,535
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		746,523,890
Entity Public Float			$ 28

CONSOLIDATED STATEMENT OF OPERA

CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net sales	$ 7,476	$ 7,196	$ 6,365
Costs of sales	5,592	5,298	4,980
Gross margin	1,884	1,898	1,385
Selling expenses	88	87	89
General and administrative expenses	318	310	338
Research and development expenses	8	14	19
Charges for integration and restructuring, closures and asset impairments (Note 18)	2	194	170
Charges (recoveries) for product remediation, net (Note 19)	0	290	0
Other operating costs (income), net (Note 20)	74	(128)	(53)
Operating income	1,394	1,131	822
Non-operating pension and other postretirement benefit (costs) credits	(272)	(62)	48
Interest income and other	60	40	65
Interest expense, net of capitalized interest	(375)	(393)	(431)
Earnings from continuing operations before income taxes	807	716	504
Income taxes (Note 21)	(59)	(134)	(89)
Earnings from continuing operations	748	582	415
Earnings from discontinued operations, net of income taxes (Note 4)	0	0	612
Net earnings	748	582	1,027
Dividends on preference shares	0	0	(22)
Net earnings attributable to Weyerhaeuser common shareholders	$ 748	$ 582	$ 1,005
Basic earnings per share attributable to Weyerhaeuser common shareholders (Note 6):
Continuing operations		$ 0.77	$ 0.55
Discontinued operations	$ 0	0	0.85
Net earnings per share	0.99	0.77	1.40
Diluted earnings per share attributable to Weyerhaeuser common shareholders (Note 6):
Continuing operations		0.77	0.55
Discontinued operations	0	0	0.84
Net earnings per share	$ 0.99	$ 0.77	$ 1.39
Weighted average shares outstanding (in thousands) (Note 6):
Basic	754,556	753,085	718,560
Diluted	756,827	756,666	722,401

CONSOLIDATED STATEMENT OF COMPR

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Comprehensive income:
Net earnings	$ 748	$ 582	$ 1,027
Other comprehensive income (loss):
Foreign currency translation adjustments	(54)	32	25
Changes in unamortized actuarial loss, net of tax expense (benefit) of $235 in 2018, ($2) in 2017 and ($151) in 2016	733	(132)	(269)
Changes in unamortized net prior service credit, net of tax benefit of $3 in 2018, $2 in 2017 and $0 in 2016	(7)	(5)	(4)
Unrealized gains on available-for-sale securities	0	2	1
Total comprehensive income	$ 1,420	$ 479	$ 780

CONSOLIDATED STATEMENT OF COM_2

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in unamortized actuarial loss, tax expense (benefit)	$ 235	$ (2)	$ (151)
Changes in unamortized net prior service credit, tax expense (benefit)	$ (3)	$ (2)	$ 0

CONSOLIDATED BALANCE SHEET

CONSOLIDATED BALANCE SHEET - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 334	$ 824
Receivables, less discounts and allowances of $1 and $1	337	396
Receivables for taxes	137	14
Inventories (Note 7)	389	383
Prepaid expenses and other current assets	152	98
Current restricted financial investments held by variable interest entities (Note 9)	253	0
Total current assets	1,602	1,715
Property and equipment, less accumulated depreciation of $3,376 and $3,338 (Note 8)	1,857	1,618
Construction in progress	136	225
Timber and timberlands at cost, less depletion	12,671	12,954
Minerals and mineral rights, less depletion	294	308
Deferred tax assets (Note 21)	15	268
Other assets	312	356
Restricted financial investments held by variable interest entities (Note 9)	362	615
Total assets	17,249	18,059
LIABILITIES AND EQUITY
Current maturities of long-term debt (Notes 13 and 14)	500	62
Current debt (nonrecourse to the company) held by variable interest entities (Note 9)	302	209
Borrowings on line of credit (Note 12 and 14)	425	0
Accounts payable	222	249
Accrued liabilities (Note 11)	490	645
Total current liabilities	1,939	1,165
Long-term debt (Notes 13 and 14)	5,419	5,930
Long-term debt (nonrecourse to the company) held by variable interest entities (Note 9)	0	302
Deferred tax liabilities	43	0
Deferred pension and other postretirement benefits (Note 10)	527	1,487
Other liabilities	275	276
Total liabilities	8,203	9,160
Weyerhaeuser shareholders’ interest (Notes 16 and 17):
Common shares: $1.25 par value; authorized 1,360 million shares; issued and outstanding: 746,391 thousand shares at December 31, 2018 and 755,223 thousand shares at December 31, 2017	933	944
Other capital	8,172	8,439
Retained earnings	1,093	1,078
Accumulated other comprehensive loss (Note 16)	(1,152)	(1,562)
Total equity	9,046	8,899
Total liabilities and equity	$ 17,249	$ 18,059

CONSOLIDATED BALANCE SHEET (Par

CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Receivables, discounts and allowances	$ 1	$ 1
Property and equipment, accumulated depreciation	$ 3,376	$ 3,338
Common shares, par value	$ 1.25	$ 1.25
Common shares, authorized	1,360,000,000	1,360,000,000
Common shares, issued	746,390,932	755,222,727
Common shares, outstanding	746,390,932	755,222,727

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operations:
Net earnings	$ 748	$ 582	$ 1,027
Noncash charges (credits) to income:
Depreciation, depletion and amortization	486	521	565
Basis of real estate sold	124	81	109
Deferred income taxes, net	72	44	(159)
Pension and other postretirement benefits	309	97	5
Share-based compensation expense (Note 17)	42	40	60
Charges for impairment of assets	1	154	37
Net gains on disposition of discontinued and other operations (Note 4)		(1)	(789)
Net gains on sale of nonstrategic assets	(16)	(16)	(73)
Gain on sale of timberlands	0	(99)	0
Change in, net of acquisition:
Receivables, less allowances	62	(35)	(54)
Receivable and payable for taxes	(103)	(50)	106
Inventories	(14)	(39)	61
Prepaid expenses and other current assets	(18)	(12)	5
Accounts payable and accrued liabilities	(154)	106	11
Pension and postretirement contributions / benefit payments	(381)	(78)	(99)
Other	(46)	(94)	(77)
Net cash from operations	1,112	1,201	735
Cash flows from investing activities:
Capital expenditures for property and equipment	(368)	(358)	(451)
Capital expenditures for timberlands reforestation	(59)	(61)	(59)
Proceeds from disposition of discontinued and other operations	0	403	2,486
Proceeds from sale of nonstrategic assets	4	26	104
Proceeds from sale of southern timberlands (Note 9)	0	203	0
Proceeds from redemption of ownership in related party (Note 9)	0	108	0
Proceeds from contribution of timberlands to related party (Note 9)	0	0	440
Other	(17)	46	39
Net cash from investing activities	(440)	367	2,559
Cash flows from financing activities:
Cash dividends on common shares	(995)	(941)	(932)
Cash dividends on preference shares	0	0	(22)
Proceeds from issuance of long-term debt (Note 13)	0	225	1,698
Payments on long-term debt (Note 13)	(62)	(831)	(2,423)
Proceeds from borrowings on line of credit (Note 12)	425	100	0
Payments on line of credit (Note 12)	0	(100)	0
Repayments of Related Party Debt	(209)	0	0
Proceeds from exercise of stock options	52	128	61
Repurchase of common shares (Note 16)	(366)	0	(2,003)
Other	(7)	(1)	(9)
Net cash from financing activities	(1,162)	(1,420)	(3,630)
Net change in cash and cash equivalents	(490)	148	(336)
Cash and cash equivalents from continuing operations at beginning of year	824	676	1,011
Cash and cash equivalents from continuing operations at end of year	334	824	676
Cash and cash equivalents from discontinued operations at beginning of year	0	0	1
Cash and cash equivalents from discontinued operations at end of year	0	0	0
Cash and cash equivalents at beginning of period	824	676	1,012
Cash and cash equivalents at end of year	334	824	676
Cash paid (received) during the year for:
Interest, net of amounts capitalized of $9 in 2018, $9 in 2017, and $8 in 2016	358	381	446
Income taxes	$ 95	$ 169	$ 485

CONSOLIDATED STATEMENT OF CAS_2

CONSOLIDATED STATEMENT OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest, amount capitalized	$ 9	$ 9	$ 8

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Millions	Total	Mandatory convertible preference shares, series A:	Common shares:	Other capital:	Retained earnings:	Accumulated other comprehensive loss:	Total equity:	Plum CreekCommon shares:	Plum CreekOther capital:
Balance at beginning of year at Dec. 31, 2015		$ 14	$ 638	$ 4,080	$ 1,349	$ (1,212)
Conversion to common shares (Note 16)		(14)
Preference shares converted to common shares (Note 16)			29
Issued for exercise of stock options			3	61
Repurchase of common shares (Note 16)	$ (2,000)		(85)	(1,918)
Release of vested restricted stock units			2
Share-based compensation				35
Plum Creek acquisition								$ 349	$ 6,046
Other transactions, net				(22)
Net earnings	1,027				1,027
Dividends on common shares					(933)
Adjustments related to new accounting pronouncements (Note 1)	0				0
Cash dividends on preference shares					(22)
Foreign currency translation adjustments	25					25
Changes in unamortized actuarial loss, net of tax (Note 10)	(269)					(269)
Changes in unamortized net prior service credit, net of tax (Note 10)	$ (4)					(4)
Unrealized gains on available-for-sale securities						1
Balance at end of year at Dec. 31, 2016		0	936	8,282	1,421	(1,459)	$ 9,180
Dividends paid per common share	$ 1.24
Conversion to common shares (Note 16)		0
Preference shares converted to common shares (Note 16)			0
Issued for exercise of stock options			7	128
Repurchase of common shares (Note 16)			0	0
Release of vested restricted stock units			1
Share-based compensation				35
Plum Creek acquisition								0	0
Other transactions, net				(6)
Net earnings	$ 582				582
Dividends on common shares					(944)
Adjustments related to new accounting pronouncements (Note 1)	0				19
Cash dividends on preference shares					0
Foreign currency translation adjustments	32					32
Changes in unamortized actuarial loss, net of tax (Note 10)	(132)					(132)
Changes in unamortized net prior service credit, net of tax (Note 10)	(5)					(5)
Unrealized gains on available-for-sale securities						2
Balance at end of year at Dec. 31, 2017	$ 8,899	0	944	8,439	1,078	(1,562)	8,899
Dividends paid per common share	$ 1.25
Conversion to common shares (Note 16)		0
Preference shares converted to common shares (Note 16)			0
Issued for exercise of stock options			3	49
Repurchase of common shares (Note 16)	$ 0		(15)	(351)
Release of vested restricted stock units			1
Share-based compensation				42
Plum Creek acquisition								$ 0	$ 0
Other transactions, net				(7)
Net earnings	748				748
Dividends on common shares					(995)
Adjustments related to new accounting pronouncements (Note 1)					262	(262)
Cash dividends on preference shares					0
Foreign currency translation adjustments	(54)					(54)
Changes in unamortized actuarial loss, net of tax (Note 10)	733					733
Changes in unamortized net prior service credit, net of tax (Note 10)	(7)					(7)
Unrealized gains on available-for-sale securities						0
Balance at end of year at Dec. 31, 2018	$ 9,046	$ 0	$ 933	$ 8,172	$ 1,093	$ (1,152)	$ 9,046
Dividends paid per common share	$ 1.32

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Our significant accounting policies describe: • our election to be taxed as a real estate investment trust, • how we report our results, • changes in how we report our results and • how we account for various items. 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. HOW WE REPORT OUR RESULTS Our report includes: • consolidated financial statements, • our business segments, • estimates, • fair value measurements and • foreign currency translation. 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. Throughout these Notes to Consolidated Financial Statements, unless specified otherwise, references to “Weyerhaeuser,” "the company," “we” and “our” refer to the consolidated company. Our Business Segments Reportable business segments are determined based on the company’s "management approach," as defined by Financial Accounting Standards Board (FASB) ASC 280, “Segment Reporting.” The management approach is based on the way the chief operating decision maker organizes the segments within a company for making decisions about resources to be allocated and assessing their performance. 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 leased recreational access Real Estate & ENR Sales of timberlands, rights to explore for and extract hard minerals, construction materials, oil and gas production, wind, solar and coal Wood Products Softwood lumber, engineered wood products, structural panels, medium density fiberboard and building materials distribution We also transfer raw materials, semi-finished 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. Unallocated Items are gains or charges related to company level initiatives or previous businesses that are not allocated to our current business segments. They include a portion of items such as share-based compensation; pension and postretirement costs; elimination of intersegment profit in inventory and LIFO; foreign exchange transaction gains and losses resulting from changes in exchange rates primarily related to our U.S. dollar denominated cash and debt balances that are held by our Canadian subsidiary; interest income and other and legacy obligations such as environmental remediation and workers compensation. 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 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; • pension plan assets measured at fair value; 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 unadjusted quoted prices for identical assets or 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. 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. CHANGES IN HOW WE REPORT OUR RESULTS Changes in how we report our results come from: • reclassification of certain balances and results from prior years to make them consistent with our current reporting and • accounting changes made upon our adoption of new accounting guidance Reclassifications We have reclassified certain balances and results from prior years to be consistent with our 2018 reporting. This makes year-to-year comparisons easier. Our reclassifications had no effect on consolidated net earnings or equity. New Accounting Pronouncements Lease Recognition In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, which requires lessees to recognize assets and liabilities for the rights and obligations created by those leases and requires 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 adopted this standard on January 1, 2019, using the modified retrospective transition approach at the beginning of the adoption period through a cumulative-effect adjustment to retained earnings. With this adoption approach, financial information will not be updated and disclosures required under the new standard will not be provided for dates and periods before January 1, 2019. In addition, the standard provides a number of optional practical expedients in transition. The adoption resulted in the recognition of additional right-of-use assets and lease liabilities for operating leases of less than 2 percent of our total assets on our Consolidated Balance Sheet . These leases are primarily related to vehicles, equipment, office and warehouse leases disclosed in Note 15: Legal Proceedings, Commitments and Contingencies . Reclassification of Certain Amounts from Accumulated Other Comprehensive Loss In February 2018, the FASB issued ASU 2018-02, which allows for the reclassification of certain income tax effects related to the Tax Cuts and Jobs Act (Tax Act) between “Accumulated other comprehensive loss” and “Retained earnings.” This ASU provides that adjustments to deferred tax liabilities and assets related to a change in tax laws be included in “Income from continuing operations”, even in situations where the related items were originally recognized in “Other comprehensive income (loss).” The amendments in this ASU are effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. Adoption of this ASU is to be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the tax laws was recognized. We adopted this ASU during first quarter 2018 using the period of adoption method, which resulted in a reclassification of $253 million from "Accumulated other comprehensive loss" to "Retained earnings" on our Consolidated Balance Sheet due to changes in federal statutory and effective state rates. In general, tax effects unrelated to the Tax Act are released from accumulated other comprehensive loss using the portfolio approach. In January 2016, the FASB issued ASU 2016-01, which updates certain aspects of recognition, measurement, presentation and disclosure of financial instruments. We adopted ASU 2016-01 in first quarter 2018, which resulted in a reclassification of accumulated unrealized gains on available-for-sale securities of $9 million from "Accumulated other comprehensive loss" to "Retained earnings" on our Consolidated Balance Sheet . Revenue Recognition In May 2014, the FASB issued 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. 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. In February 2017, FASB issued ASU 2017-05, which clarifies the scope of ASC 610-20 and affects accounting for partial sales of nonfinancial assets. We adopted this accounting standard update on 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 have adopted using the cumulative effect method. The adoption of the new revenue recognition guidance does not materially affect our Consolidated Statement of Operations , Consolidated Balance Sheet , or Consolidated Statement of Cash Flows . HOW WE ACCOUNT FOR VARIOUS ITEMS This section provides information about how we account for certain key items related to: • capital investments, • financing our business and • operations. ITEMS RELATED TO CAPITAL INVESTMENTS Key items related to accounting for capital investments pertain to property and equipment, timber and timberlands, impairment of long-lived assets and goodwill. 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. • We capitalize costs associated with logging roads that we intend to utilize for a period longer than one year. These roads are then amortized over an estimated service life. • Cost and accumulated depreciation of property sold or retired are removed from the accounts and the gain or loss is included in earnings. Timber and Timberlands We carry timber and timberlands at cost less depletion. 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. 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. In addition, the duration of the harvest cycle varies by geographic region and species of timber. Depletion rate calculations do not include estimates for: • future silviculture or sustainable forest management costs associated with existing stands • future reforestation costs associated with a stand's final harvest; and • future volume in connection with the replanting of a stand subsequent to its final harvest 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 Costs of sales. 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 the carrying value of long-lived assets whenever an event or a change in circumstance ("a triggering event") indicates that the carrying value of the asset or asset group may not be recoverable through future operations. The carrying value is the original cost, less accumulated depreciation and any past impairments recorded. 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. ITEMS RELATED TO FINANCING OUR BUSINESS Key items related to financing our business include financial instruments, cash and cash equivalents, accounts payable and concentration of risk. 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. 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 may have negative book cash balances due to outstanding checks that have not yet been paid by the bank. These negative balances would be included in "Accounts payable" on our Consolidated Balance Sheet . Changes in these negative cash balances would be reported as financing activities in our Consolidated Statement of Cash Flows . We had no negative book cash balances as of December 31, 2018 , and December 31, 2017 . Concentration of Risk We disclose customers that represent a concentration of risk. As of December 31, 2018 , and December 31, 2017 , no customer accounted for 10 percent or more of our net sales. ITEMS RELATED TO OPERATIONS Key items related to operations include revenue recognition, inventories, shipping and handling costs, income taxes, pension and other postretirement plans and environmental remediation. Revenue Recognition Refer to Note 3: Revenue Recognition for detail on how we account for revenue. Inventories We state inventories at the lower of cost or net realizable value. 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 sales" 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 reporting 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. 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 defined benefit pension plans covering approximately half of our employees. Determination of benefits differs for salaried, hourly and union employees, as follows: • 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 10: Pension and Other Postretirement Benefit Plans provides additional information about changes made in our postretirement benefit plans during 2018 and 2017 . 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.

BUSINESS SEGMENTS

BUSINESS SEGMENTS	12 Months Ended
	Dec. 31, 2018
BUSINESS SEGMENTS	BUSINESS SEGMENTS Our business segments and how we account for those segments are discussed in Note 1: Summary of Significant Accounting Policies . This note provides key financial data by business segment. KEY FINANCIAL DATA BY BUSINESS SEGMENT Sales and Contribution (Charge) to Earnings DOLLAR AMOUNTS IN MILLIONS TIMBERLANDS REAL ESTATE WOOD UNALLOCATED ITEMS (1) AND INTERSEGMENT ELIMINATIONS CONSOLIDATED Sales to unaffiliated customers 2018 $ 1,915 $ 306 $ 5,255 $ — $ 7,476 2017 $ 1,942 $ 280 $ 4,974 $ — $ 7,196 2016 $ 1,805 $ 226 $ 4,334 $ — $ 6,365 Intersegment sales 2018 $ 802 $ 1 $ — $ (803 ) $ — 2017 $ 762 $ 1 $ — $ (763 ) $ — 2016 $ 840 $ 1 $ 68 $ (909 ) $ — Contribution (charge) to earnings from continuing operations 2018 $ 583 $ 127 $ 838 $ (366 ) $ 1,182 2017 $ 532 $ 146 $ 569 $ (138 ) $ 1,109 2016 $ 499 $ 55 $ 512 $ (131 ) $ 935 (1) Unallocated items are gains or charges not related to or allocated to an individual operating segment. They include a portion of items such as share-based compensation expense, pension and postretirement costs, foreign exchange transaction gains and losses, interest income and other, and the elimination of intersegment profit in inventory and LIFO. Management evaluates segment performance based on the contributions to earnings of the respective segments. An analysis and reconciliation of our business segment information to the consolidated financial statements follows: Reconciliation of Contribution to Earnings to Net Earnings DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Net contribution to earnings from continuing operations $ 1,182 $ 1,109 $ 935 Net contribution to earnings from discontinued operations — — 957 Total contribution to earnings 1,182 1,109 1,892 Interest expense, net of capitalized interest (1) (375 ) (393 ) (436 ) Income before income taxes (1) 807 716 1,456 Income taxes (1) (59 ) (134 ) (429 ) Net earnings $ 748 $ 582 $ 1,027 (1) Results shown for 2016 include amounts for both continuing and discontinued operations. Refer to Note 4: Discontinued Operations and Other Divestitures for further information. Additional Financial Information DOLLAR AMOUNTS IN MILLIONS TIMBERLANDS REAL ESTATE & ENR WOOD PRODUCTS UNALLOCATED ITEMS CONSOLIDATED Depreciation, depletion and amortization 2018 $ 319 $ 14 $ 149 $ 4 $ 486 2017 $ 356 $ 15 $ 145 $ 5 $ 521 2016 $ 366 $ 13 $ 129 $ 4 $ 512 Charges for integration and restructuring, closures and asset impairments (1) 2018 $ — $ — $ 2 $ — $ 2 2017 $ 147 $ — $ 13 $ 34 $ 194 2016 $ — $ 15 $ 7 $ 148 $ 170 Capital expenditures 2018 $ 117 $ — $ 306 $ 4 $ 427 2017 $ 115 $ 2 $ 299 $ 3 $ 419 2016 $ 116 $ 1 $ 297 $ 11 $ 425 (1) See Note 18: Charges for Integration and Restructuring, Closures and Asset Impairments for more information. Total Assets DOLLAR AMOUNTS IN MILLIONS TIMBERLANDS and REAL ESTATE & ENR (1) WOOD PRODUCTS UNALLOCATED ITEMS CONSOLIDATED Total assets 2018 $ 13,838 $ 2,234 $ 1,177 $ 17,249 2017 $ 14,122 $ 2,145 $ 1,792 $ 18,059 (1) Assets attributable to the Real Estate & ENR business segment are combined with total assets for the Timberlands segment as we do not produce separate balance sheets internally. DISCONTINUED OPERATIONS During 2016, we disposed of our former Cellulose Fibers segment, which is excluded from the segment results above unless otherwise noted. See Note 4: Discontinued Operations and Other Divestitures for information regarding our discontinued operations and the segments affected.

REVENUE RECOGNITION (Notes)

REVENUE RECOGNITION (Notes)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION	REVENUE RECOGNITION A majority of our revenue is derived from sales of delivered logs and manufactured wood products. We account for revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers , which we adopted on January 1, 2018, using the cumulative effect method. The adoption of the new revenue recognition guidance did not materially affect our Consolidated Statement of Operations , Consolidated Balance Sheet , or Consolidated Statement of Cash Flows . PERFORMANCE OBLIGATIONS A performance obligation, as defined in ASC Topic 606, is a promise in a contract to transfer a distinct good or service to a customer. A contract's transaction price is allocated to each distinct performance obligation and recognized as revenue at the point in time, or over the period, in which the performance obligation is satisfied. Performance obligations associated with delivered log sales are typically satisfied when the logs are delivered to our customers’ mills or delivered to an ocean vessel in the case of export sales. Performance obligations associated with the sale of wood products are typically satisfied when the products are shipped. The company has elected, as an accounting policy, to treat shipping and handling that is performed after a customer obtains control of the product as an activity required to fulfill the promise to transfer the good; therefore we will not evaluate this requirement as a separate performance obligation. Customers are generally invoiced shortly after logs are delivered or after wood products are shipped, with payment generally due within a month or less of the invoice date. ASC Topic 606 requires entities to consider significant financing components of contracts with customers, though allows for the use of a practical expedient when the period between satisfaction of a performance obligation and payment receipt is one year or less. Given the nature of our revenue transactions, we have elected to utilize this practical expedient. Performance obligations associated with real estate sales are generally met when placed into escrow and all conditions of closing have been satisfied. CONTRACT ESTIMATES Substantially all of the company’s performance obligations are satisfied as of a point in time. Therefore, there is little judgment in determining when control transfers for our business segments as described above. The transaction price for log sales generally equals the amount billed to our customer for logs delivered during the accounting period. For the limited number of log sales subject to a long-term supply agreement, the transaction price is variable but is known at the time of billing. For wood products sales, the transaction price is generally the amount billed to the customer for the products shipped but may be reduced slightly for estimated cash discounts and rebates. There are no significant contract estimates related to the real estate business. CONTRACT BALANCES In general, customers are billed and a receivable is recorded as we ship and/or deliver wood products and logs. We generally receive payment shortly after products have been received by our customers. Contract asset and liability balances are immaterial. For real estate sales, the company receives the entire consideration in cash at closing. MAJOR PRODUCTS A Reconciliation of Revenue Recognized by our Major Products: DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Net Sales to Unaffiliated Customers: Timberlands Segment Delivered logs (1) : West Domestic sales 503 473 410 Export sales 484 442 455 Subtotal West 987 915 865 South 625 616 566 North 99 95 91 Other 41 59 38 Subtotal delivered logs sales 1,752 1,685 1,560 Stumpage and pay-as-cut timber 59 73 85 Recreational and other lease revenue 59 59 44 Other (2) 45 125 116 Net Sales attributable to Timberlands Segment 1,915 1,942 1,805 Real Estate & ENR Segment Real estate 229 208 172 Energy and natural resources 77 72 54 Net sales attributable to Real Estate & ENR Segment 306 280 226 Wood Products Segment Structural lumber 2,258 2,058 1,839 Oriented strand board 891 904 707 Engineered solid section 521 500 450 Engineered I-joists 336 336 290 Softwood plywood 200 176 174 Medium density fiberboard 177 183 158 Complementary building products 584 541 515 Other (3) 288 276 201 Net sales attributable to Wood Products Segment 5,255 4,974 4,334 Total $ 7,476 $ 7,196 $ 6,365 (1) The West region includes Washington and Oregon. The South region includes Virginia, North Carolina, South Carolina, Florida, Georgia, Alabama, Mississippi, Louisiana, Arkansas, Texas and Oklahoma. The North region includes West Virginia, Maine, New Hampshire, Vermont, Michigan, Wisconsin and Montana. Other includes our Canadian operations and former Twin Creeks Venture (terminated in December 2017). (2) Other Timberlands sales include sales of seeds and seedlings, chips, as well as sales from our former Uruguayan operations (sold during third quarter 2017). Our former Uruguayan operations included logs, plywood and hardwood lumber harvested or produced. Refer to Note 4: Discontinued Operations and Other Divestitures for further information. (3) Includes chips and other byproducts.

DISCONTINUED OPERATIONS AND OTH

DISCONTINUED OPERATIONS AND OTHER DIVESTITURES	12 Months Ended
	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
DISCONTINUED OPERATIONS AND OTHER DIVESTITURES	DISCONTINUED OPERATIONS AND OTHER DIVESTITURES OPERATIONS DIVESTED On September 1, 2017, we completed the sale of our Uruguay timberlands and manufacturing operations, to a consortium led by BTG Pactual's Timberland Investment Group (TIG), including other long-term investors, for $403 million of cash proceeds. Due to the impairment of our Uruguayan operations recorded during second quarter 2017 (refer to Note 18: Charges for Integration and Restructuring, Closures and Asset Impairments ), no material gain or loss was recorded as a result of this sale. The sale of our Uruguayan operations was not considered a strategic shift that had or will have a major effect on our operations or financial results and therefore did not meet the requirements for presentation as discontinued operations. DISCONTINUED OPERATIONS During 2016, we entered into three separate transactions to sell our Cellulose Fibers business. As a result of these transactions, the company recognized a pretax gain on disposition of $789 million and total cash proceeds of $2.5 billion in the second half of 2016. These transactions consisted of: • sale of our Cellulose Fibers liquid packaging board business to Nippon Paper Industries Co., Ltd for $285 million in cash proceeds, which closed on August 31, 2016; • sale of our Cellulose Fibers printing papers joint venture to One Rock Capital Partners, LLC for $42 million in cash proceeds, which closed on November 1, 2016; and • sale of our Cellulose Fibers pulp business to International Paper for $2.2 billion in cash proceeds, which closed on December 1, 2016. The results of operations for our pulp and liquid packaging board businesses, along with our interest in our printing papers joint venture, were reclassified to discontinued operations during our 2016 reporting year. These results have been summarized in "Earnings from discontinued operations, net of income taxes" on our Consolidated Statement of Operations for each period presented. We did not reclassify our Consolidated Statement of Cash Flows to reflect discontinued operations. Cellulose Fibers was previously disclosed as a separate reportable business segment. Retained indirect corporate overhead costs previously allocated to Cellulose Fibers are now reported as part of Unallocated Items. We used $1.7 billion of the after-tax proceeds from the sale of our Cellulose Fibers business segment for repayment of debt during 2016. The following table presents the components of the net gain on the divestiture of Cellulose Fibers: DOLLAR AMOUNTS IN MILLIONS 2016 Proceeds, net of cash and cash equivalents disposed of $ 2,486 Less: Net book value of assets and liabilities disposed of (1,678 ) Transaction costs, net of reimbursement (19 ) (1,697 ) Pretax gain on Cellulose Fibers divestitures 789 Income taxes (243 ) Net gain on Cellulose Fibers divestitures $ 546 NET EARNINGS FROM DISCONTINUED OPERATIONS Sales and Net Earnings from Discontinued Operations DOLLAR AMOUNTS IN MILLIONS 2016 (1) Total net sales $ 1,537 Costs of sales 1,283 Gross margin 254 Selling expenses 12 General and administrative expenses 29 Research and development expenses 5 Charges for integration and restructuring, closures and asset impairments (2) 63 Other operating income, net (27 ) Operating income 172 Equity loss from joint venture (4 ) Interest expense, net of capitalized interest (5 ) Earnings from discontinued operations before income taxes 163 Income taxes (97 ) Net earnings from operations 66 Net gain on divestiture of Cellulose Fibers 546 Net earnings from discontinued operations $ 612 (1) Discontinued operations in 2016 includes 335 days of the pulp business, 305 days of our printing papers joint venture operations, and 244 days of the liquid packaging board business. (2) Charges for integration and restructuring, closures and asset impairments consist of costs related to our strategic evaluation of the Cellulose Fibers businesses and transaction-related costs. Results of discontinued operations exclude certain general corporate overhead costs that have been allocated to and are included in contribution to earnings for the operating segments. CASH FLOWS FROM DISCONTINUED OPERATIONS Cash Flows from Discontinued Operations DOLLAR AMOUNTS IN MILLIONS 2016 (1) Net cash provided by operating activities $ 196 Net cash provided by investing activities $ 2,356 (1) Discontinued operations in 2016 includes 335 days of the pulp business, 305 days of our printing papers joint venture operations, and 244 days of the liquid packaging board business, and the cash flows associated with the CF divestitures. RELATED PARTY TRANSACTIONS WITH PRINTING PAPERS JOINT VENTURE Prior to November 1, 2016, we held a 50 percent ownership interest in North Pacific Paper Corporation (NORPAC), our printing papers joint venture, which we considered a related party. We provided goods and services to NORPAC, including raw materials and support services. The amount paid to Weyerhaeuser by this joint venture for goods and services was $126 million in 2016 .

MERGER WITH PLUM CREEK MERGER W

MERGER WITH PLUM CREEK MERGER WITH PLUM CREEK	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
MERGER WITH PLUM CREEK	MERGER WITH PLUM CREEK On February 19, 2016, we merged with Plum Creek Timber Company, Inc. (Plum Creek). Plum Creek was a REIT that primarily owned and managed timberlands in the United States. Plum Creek also produced wood products, developed opportunities for mineral and other natural resource extraction, and sold real estate properties. The acquisition of total assets of $10.0 billion was a noncash investing and financing activity comprised of $6.4 billion in equity consideration transferred and $3.6 billion of liabilities assumed. Summarized Unaudited Pro Forma Information that Presents Combined Amounts as if this Merger Occurred at the Beginning of 2015 DOLLAR AMOUNTS IN MILLIONS, EXCEPT PER-SHARE FIGURES 2016 Net sales $ 6,525 Net earnings from continuing operations attributable to Weyerhaeuser common shareholders $ 519 Net earnings from continuing operations per share attributable to Weyerhaeuser common shareholders, basic $ 0.69 Net earnings from continuing operations per share attributable to Weyerhaeuser common shareholders, diluted $ 0.68 Pro forma net earnings attributable to Weyerhaeuser common shareholders exclude $155 million of non-recurring merger-related costs (net of tax) incurred in the year ended December 31, 2016 . Pro forma data may not be indicative of the results that would have been obtained had these events occurred at the beginning of the period presented, nor is it intended to be a projection of future results.

NET EARNINGS PER SHARE

NET EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2018
NET EARNINGS PER SHARE	NET EARNINGS PER SHARE Our basic earnings per share attributable to Weyerhaeuser common shareholders for the last three years were: • $0.99 in 2018 , • $0.77 in 2017 and • $1.40 in 2016 . Our diluted earnings per share attributable to Weyerhaeuser common shareholders for the last three years were: • $0.99 in 2018 , • $0.77 in 2017 and • $1.39 in 2016 . HOW WE CALCULATE BASIC AND DILUTED NET 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 and • performance share units. Calculation of Weighted Average Number of Outstanding Common Shares - Dilutive SHARES IN THOUSANDS 2018 2017 2016 Weighted average number of outstanding shares - basic 754,556 753,085 718,560 Dilutive potential common shares: Stock options 1,310 2,571 2,672 Restricted stock units 566 582 756 Performance share units 395 428 413 Total effect of outstanding dilutive potential common shares 2,271 3,581 3,841 Weighted average number of outstanding common shares - dilutive 756,827 756,666 722,401 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. SHARES EXCLUDED FROM DILUTIVE EFFECT The following shares were not included in the computation of diluted earnings per share because they were either antidilutive or the required performance or market conditions were not met. Some or all of these shares may be dilutive potential common shares in future periods. Potential Shares Not Included in the Computation of Diluted Earnings per Share SHARES IN THOUSANDS 2018 2017 2016 Stock options 2,402 1,351 1,462 Performance share units 1,080 799 384

INVENTORIES

INVENTORIES	12 Months Ended
	Dec. 31, 2018
INVENTORIES	INVENTORIES Inventories include raw materials, work-in-process, finished goods as well as materials and supplies. Inventories as of the End of Our Last Two Years DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, LIFO inventories: Logs $ 11 $ 17 Lumber, plywood, panels, and fiberboard 75 66 Other products 10 10 FIFO or moving average cost inventories: Logs 35 38 Lumber, plywood, panels, fiberboard and engineered wood products 86 91 Other products 83 77 Materials and supplies 89 84 Total $ 389 $ 383 LIFO — the last-in, first-out method — applies to major inventory products held at our U.S. domestic locations. The FIFO — the first-in, first-out method — or moving average cost methods apply to the balance of our domestic raw material and product inventories as well as for all material and supply inventories and all foreign inventories. If we used FIFO for all LIFO inventories, our stated inventories would have been higher by $79 million as of December 31, 2018 , and $70 million as of December 31, 2017 . HOW WE ACCOUNT FOR OUR INVENTORIES The Inventories section of Note 1: Summary of Significant Accounting Policies provides details about how we account for our inventories.

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	PROPERTY AND EQUIPMENT Property and equipment includes land, buildings and improvements, machinery and equipment, roads and other items. Carrying Value of Property and Equipment and Estimated Service Lives DOLLAR AMOUNTS IN MILLIONS RANGE OF LIVES DECEMBER 31, DECEMBER 31, Property and equipment, at cost: Land N/A $ 87 $ 88 Buildings and improvements 15-40 942 867 Machinery and equipment 5-25 3,240 3,037 Roads 10-35 785 782 Other 3-10 179 182 Total cost 5,233 4,956 Accumulated depreciation and amortization (3,376 ) (3,338 ) Property and equipment, net $ 1,857 $ 1,618 SERVICE LIVES AND DEPRECIATION In general, additions are classified into components, each with its own estimated useful life as determined at the time of purchase. Buildings and improvements for property and equipment have estimated lives that are generally at either the low end or high end of the range from 15 years to 40 years , depending on the type and performance of construction. Depreciation expense was: • $197 million in 2018 , • $206 million in 2017 and • $198 million in 2016 (excluding discontinued operations).

RELATED PARTIES

RELATED PARTIES	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
RELATED PARTIES	RELATED PARTIES This note provides details about and our transactions with related parties. For the years presented, our related parties have consisted of: • Real Estate Development Ventures, • our Twin Creeks Venture, and • special-purpose entities (SPEs). REAL ESTATE DEVELOPMENT VENTURE WestRock-Charleston Land Partners, LLC (WR-CLP) is a limited liability company which holds residential and commercial real estate development properties, currently under development (Class A Properties) and higher-value timber and development lands (Class B Properties) (referred to collectively as the Real Estate Development Ventures). The company uses the equity method for both its Class A and Class B interests of 3 percent and 50 percent , respectively. Our share of the equity earnings is included in the net contribution to earnings of our Real Estate & ENR segment. We are not the primary beneficiary of WR-CLP and we are not committed to make any material capital contributions during the remaining term of the venture, which expires in 2020 . We do not intend to provide any additional sources of financing for WR-CLP. The carrying amount of our investment in WR-CLP was $31 million at December 31, 2017 . During 2018, all remaining capital invested in WR-CLP was returned through distributions. At December 31, 2018 , we no longer carry an investment related to WR-CLP. Additionally, we had a $1 million gain on investment from the joint venture during 2018. We record our share of net earnings on the investment within "Interest income and other" in our Consolidated Statement of Operations in the period which earnings are recorded by the affiliates. TWIN CREEKS VENTURE Ownership Redemption, Agreement Termination and Sale Recognition During October 2017, we redeemed our 21 percent ownership interest in the Twin Creeks Venture for $108 million in cash. We did not recognize a material gain or loss on the redemption of our ownership interest. The cash received was classified as a cash flow from investing activities in our Consolidated Statement of Cash Flows . Effective December 31, 2017 , we terminated the agreements under which we had managed the Twin Creeks timberlands. Following termination of these agreements, Weyerhaeuser has no further responsibilities or obligations related to the Twin Creeks Venture and our continuing involvement in the contributed timberlands ceased. In fourth quarter 2017, we recognized the sale of the original contribution of timberlands that occurred April 2016. Changes in our deposit from contribution of timberlands to related party balance during 2017 were as follows: DOLLAR AMOUNTS IN MILLIONS Balance at December 31, 2016 $ 426 Lease payments to Twin Creeks Venture (8 ) Distributions from Twin Creeks Venture 2 Recognition of contributed timberlands (420 ) Balance at December 31, 2017 $ — Formation and Operations On April 1, 2016, we contributed approximately 260,000 acres of our Southern timberlands with an agreed-upon value of approximately $560 million to Twin Creeks Timber, LLC (Twin Creeks Venture), in exchange for cash of approximately $440 million and a 21 percent ownership interest. The other members contributed cash of approximately $440 million for a combined 79 percent ownership interest. In conjunction with contributing to the venture, we entered into a separate agreement to manage the timberlands owned by the Twin Creeks Venture, including harvesting activities, marketing and log sales activities, and replanting and silviculture activities. This management agreement guaranteed the Twin Creeks Venture an annual return equal to 3 percent of the contributed value of the managed timberlands in the form of minimum quarterly payments from Weyerhaeuser. This agreement also required us to annually distribute 75 percent of any profits earned by us in excess of the minimum quarterly payments. The management agreement was cancellable at any time by Twin Creeks Timber, LLC, and otherwise would expire on April 1, 2019. The guaranteed return that the management agreement required Weyerhaeuser to provide to the Twin Creeks Venture constituted continuing involvement in the timberlands that we contributed to the venture. This continuing involvement prohibited the recognition of the contribution as a sale and required application of the deposit method to account for the cash payment received. By applying the deposit method to the contribution of timberlands to the venture: • Our receipt of $440 million proceeds from the contribution of timberlands to the venture was recorded as a noncurrent liability. • The contributed timberlands continued to be reported within the "Timber and timberlands at cost, less depletion charged to disposals" on our balance sheet as of December 31, 2016. • No gain or loss was recognized related to the formation or redemption in our Consolidated Statement of Operations . • Our balance sheet as of December 31, 2016 did not reflect our 21 percent ownership interest in the Twin Creeks Venture. The receipt of $440 million in 2016 was classified as a cash flow from investing activities in our Consolidated Statement of Cash Flows . The cash proceeds from our contribution of timberlands were used for share repurchases. Sale of Additional Timberlands to Twin Creeks In conjunction with the redemption and termination discussed above, we also entered an agreement to sell 100,000 acres of Southern timberlands to Twin Creeks for $203 million . The sale, which included 80,000 acres of timberlands in Mississippi and 20,000 acres in Georgia, closed December 29, 2017. The sale resulted in a $99 million gain recognized during fourth quarter 2017. SPECIAL-PURPOSE ENTITIES From 2002 through 2004, we sold certain nonstrategic timberlands. As a result of these sales, buyer-sponsored and monetization special purpose entities (SPEs) were formed. We are the primary beneficiary and consolidate the assets and liabilities of the SPEs involved in these transactions. The assets of the buyer-sponsored SPEs are financial investments which consist of bank guarantees. These bank guarantees are in turn backed by bank notes, which are the liabilities of the monetization SPEs. Interest earned from the financial investments within the buyer-sponsored SPEs is used to pay interest accrued on the corresponding monetization SPE’s note. We have an equity interest in the monetization SPEs, but no ownership interest in the buyer-sponsored SPEs. The following disclosures refer to assets of buyer-sponsored SPEs and liabilities of monetization SPEs. However, because these SPEs are distinct legal entities: • Assets of the SPEs are not available to satisfy our liabilities or obligations. • Liabilities of the SPEs are not our liabilities or obligations. Our Consolidated Balance Sheet as of December 31, 2018 includes: • Assets from our buyer-sponsored SPEs, which consist of: – $253 million , due first quarter 2019 and – $362 million , due first quarter 2020 . • Liabilities from our monetization SPEs, which consist of: – $302 million , due third quarter 2019 . During fourth quarter 2018, we paid $209 million related to liabilities from our monetized SPEs at maturity. Our Consolidated Statement of Operations includes: • Interest income on buyer-sponsored SPE investments of: – $34 million in 2018 , – $34 million in 2017 and – $34 million in 2016 . • Interest expense on monetization SPE notes of: – $29 million in 2018 , – $29 million in 2017 and – $29 million in 2016 . The weighted average interest rate on our buyer-sponsored SPEs was 5.5 percent during 2018 and 2017 . The weighted average interest rate on our monetization SPEs was 5.6 percent during 2018 and 2017 .

PENSION AND OTHER POSTRETIREMEN

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS	12 Months Ended
	Dec. 31, 2018
PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS	PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS This note provides details about defined benefit and defined contribution plans we sponsor for our employees. The "Pension and Other Postretirement Benefit Plans" section of Note 1: Summary of Significant Accounting Policies provides information about employee eligibility for pension plans and postretirement health care and life insurance benefits, as well as how we account for the plans and benefits. DEFINED BENEFIT PLANS WE SPONSOR OVERVIEW OF PLANS The defined benefit pension plans we sponsor in the U.S. and Canada differ according to each country’s requirements. In the U.S., we have plans that qualify under the Internal Revenue Code (qualified plans), as well as plans for select employees that provide additional benefits not qualified under the Internal Revenue Code (nonqualified plans). In Canada, we have plans that are registered under the Income Tax Act and applicable provincial pension acts (registered plans), as well as nonregistered plans for select employees that provide additional benefits that may not be registered under the Income Tax Act or provincial pension acts (nonregistered plans). We also offer other postretirement benefit plans in the U.S. and Canada , including retiree medical and life insurance plans. Actions to Reduce Pension Plan Obligations During 2018, we offered select U.S. terminated vested plan participants the opportunity to elect an immediate lump sum distribution. Lump sum distributions were paid from plan assets totaling $664 million during fourth quarter 2018. In connection with this transaction, we have recorded a settlement charge of $200 million during fourth quarter 2018, accelerating the recognition of previously unrecognized losses in “Accumulated other comprehensive loss”, that would have been recognized in subsequent periods. The settlement triggered a plan remeasurement, however due to the short period between the settlement and our normal year-end remeasurement, the effects were insignificant to the net periodic benefit costs and therefore not recorded. In January 2019, we transferred approximately $1.5 billion of U.S. qualified pension plan assets and liabilities to an insurance company through the purchase of a group annuity contract. We expect to record an additional settlement charge of approximately $450 million in connection with this transaction during first quarter 2019. To maintain the U.S. qualified pension plan's current funded status in connection with these transactions, we contributed $300 million to the plan during third quarter 2018 . Refer to Note 21: Income Taxes for details on the tax effects of this transaction. FUNDED STATUS OF PLANS The funded status of the plans we sponsor is determined by comparing the projected benefit obligation with the fair value of plan assets at the end of the year. The following table demonstrates how our plans' funded status is reflected on the Consolidated Balance Sheet . DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS 2018 2017 2018 2017 Funded status: Fair value of plan assets $ 4,930 $ 5,514 $ 18 $ — Projected benefit obligations (5,263 ) (6,795 ) (166 ) (200 ) Funded status $ (333 ) $ (1,281 ) $ (148 ) $ (200 ) Presentation on our Consolidated Balance Sheet: Noncurrent assets $ 74 $ 45 $ — $ — Current liabilities (18 ) (21 ) (10 ) (19 ) Noncurrent liabilities (389 ) (1,305 ) (138 ) (181 ) Funded status $ (333 ) $ (1,281 ) $ (148 ) $ (200 ) Assets and liabilities on the Consolidated Balance Sheet are different from the cumulative income or expense that we have recorded associated with the plans. The differences are actuarial gains and losses and prior service costs and credits that are deferred and amortized into periodic benefit costs in future periods. Unamortized amounts are recorded in "Accumulated Other Comprehensive Loss", which is a component of total equity on our Consolidated Balance Sheet . The "Accumulated Other Comprehensive Income (Loss)" section of Note 16: Shareholder's Interest details changes in these amounts by component. Changes in Fair Value of Plan Assets DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS 2018 2017 2018 2017 Fair value of plan assets at beginning of year (estimated) $ 5,514 $ 5,351 $ — $ — Adjustment for final fair value of plan assets 44 18 — — Actual return on plan assets 123 553 — — Foreign currency translation (73 ) 59 — — Employer contributions and benefit payments 345 57 36 20 Plan participants’ contributions — — 4 6 Plan transfers 1 3 — — Benefits paid (includes lump sum settlements) (1,024 ) (527 ) (22 ) (26 ) Fair value of plan assets at end of year (estimated) $ 4,930 $ 5,514 $ 18 $ — We estimate the fair value of pension plan assets based upon the information available during the year-end reporting process. In some cases, primarily with regard to private equity funds, the available information consists of net asset values as of an interim date, plus cash flows and market events between the interim date and the end of the year. We update the year-end estimated fair value of pension plan assets during the first half of the next year to incorporate year-end net asset values received after we have filed our Annual Report on Form 10-K. During second quarter 2018, we recorded an increase in the beginning of year fair value of the pension assets of $44 million , or less than 1 percent. During second quarter 2018, we also updated our mortality assumption and census data used to estimate our projected benefit obligation for our U.S. qualified pension plan. We recorded an adjustment to our projected benefit obligation, incorporating updated census data and applying new company-specific mortality data. As a result of these updates, the beginning of year pension projected benefit obligation decreased by $155 million , or approximately 2 percent. The net effect of these updates, including the update to the pension assets, was a $199 million improvement in funded status See additional details about the changes in the fair value of plan assets in the "Pension Assets" section below. Changes in Projected Benefit Obligations of Our Pension and Other Postretirement Benefit Plans DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS 2018 2017 2018 2017 Reconciliation of projected benefit obligation: Projected benefit obligation beginning of year $ 6,795 $ 6,469 $ 200 $ 225 Service cost 37 35 — — Interest cost 236 264 7 8 Plan participants’ contributions — — 4 6 Actuarial (gains) losses (718 ) 489 (18 ) (18 ) Foreign currency translation (69 ) 59 (5 ) 5 Benefits paid (includes lump sum settlements) (1,024 ) (527 ) (22 ) (26 ) Plan amendments and other 5 3 — — Plan transfers 1 3 — — Projected benefit obligation at end of year $ 5,263 $ 6,795 $ 166 $ 200 See additional details about the actuarial assumptions and changes in the projected benefit obligation in the "Actuarial Assumptions" section below. Accumulated Benefit Obligations Greater Than Plan Assets As of December 31, 2018 , pension plans with accumulated benefit obligations greater than plan assets had: • $4.5 billion in projected benefit obligations, • $4.4 billion in accumulated benefit obligations and • assets with a fair value of $4.1 billion . As of December 31, 2017 , pension plans with accumulated benefit obligations greater than plan assets had: • $5.9 billion in projected benefit obligations, • $5.9 billion in accumulated benefit obligations and • assets with a fair value of $4.6 billion . The accumulated benefit obligation for all of our defined benefit pension plans was: • $5.2 billion at December 31, 2018 , and • $6.7 billion at December 31, 2017 . PENSION ASSETS Our Investment Policies and Strategies Our investment policies and strategies guide and direct how the funds are managed for the benefit plans we sponsor. These funds include our: • U.S. Pension Trust — funds our U.S. qualified pension plans; • Canadian Pension Trust — funds our Canadian registered pension plans; and • Retirement Compensation Arrangements — fund a portion of our Canadian nonregistered pension plans. U.S. and Canadian Pension Trusts As of the end of 2018, we have begun to shift pension plan assets to an allocation that will more closely match the pension plan liability profile going forward. The former investment strategy included investments in hedge funds, private equity funds, derivative instruments and other investments. These asset classes are now generally in redemption and run-off mode however, given the long-term nature of these investments, they will continue to comprise a significant portion of the plan assets for several years. We expect all investments in redemption to be redeemed at amounts materially consistent with their net asset values. As these investments are redeemed or liquidated, cash proceeds available for investment will be invested in accordance with our revised investment strategy. The revised investment strategy targets an initial 60 percent allocation to growth assets and a 40 percent allocation to liability hedging assets. We expect to increase the allocation to liability hedging assets over time as the funded status of the pension plan improves. Growth assets include new investments in global equities, hedge funds, which are generally in redemption, and private equity assets, which are generally in run-off mode. Liability hedging assets include corporate credit and government issued fixed income securities, treasury futures and interest rate swaps selected to align with the plan liabilities. Cash and short-term investments include highly liquid money market and government securities and are primarily held to fund benefit payments, capital calls, margin requirements or to meet regulatory requirements. Cash at December 31, 2018, includes amounts that will be invested in liability hedging assets such as fixed income investments. Fixed income investments include publicly traded corporate and government issued debt. These bonds have varying maturities, credit quality and sector exposure, and are selected to align with the duration of our plan liabilities. The fixed income investments are invested largely in line with long corporate bond indices. Hedge fund and related investments are privately-offered managed pools primarily structured as limited liability entities. General members or partners of these limited liability entities serve as portfolio managers and are thus responsible for the fund’s underlying investment decisions. Underlying investments within these funds may include long and short public and private equities, corporate, mortgage and sovereign debt, options, swaps, forwards and other derivative positions. These funds have varying degrees of leverage, liquidity, and redemption provisions. Private equity and related investments are investments in private equity, mezzanine, distressed, co-investments and other structures. Private equity funds generally participate in buyouts and venture capital of limited liability entities through unlisted equity and debt instruments. These funds may also borrow at the underlying entity level. Mezzanine and distressed funds generally invest in the debt of public or private companies with additional participation through warrants or other equity options. Derivative instruments are comprised of swaps, futures, forwards or options. Equity and fixed income index derivatives are used to achieve target equity and bond exposure or to reduce exposure to certain market risks. Foreign currency derivatives reduce exposure to certain currency risks. Total return swaps enable exposure to return characteristics of specific financial strategies with limited exchange of principal. Assets within our qualified and registered pension plans in our U.S. and Canadian pension trusts were invested as follows: DECEMBER 31, 2018 DECEMBER 31, 2017 Cash and short-term investments 5.8 % 10.6 % Fixed income investments: Corporate 21.5 — Government 8.6 — Hedge funds and related investments 36.9 58.8 Private equity and related investments 21.9 22.2 Derivative instruments, net 5.6 8.7 Accrued liabilities (0.3 ) (0.3 ) Total 100.0 % 100.0 % Retirement Compensation Arrangements Retirement compensation arrangements fund a portion of our Canadian nonregistered pension plans. As required by Canadian tax rules, approximately 50 percent of these assets are invested into a noninterest-bearing refundable tax account held by the Canada Revenue Agency. This portion of the portfolio does not earn returns. The remaining portion is invested in a portfolio of equities. Managing Risk Investments and contracts are subject to risks including market price, liquidity, currency, interest rate and credit risks. The following provides an overview of these risks and describes governance processes and actions we take to mitigate these risks on our pension plan asset portfolios. Market price risk is the risk that market fluctuations will adversely affect the value of plan assets. The trusts mitigate market price risk by investing in a diversified portfolio. In addition, we and our investment advisers perform regular monitoring with ongoing qualitative assessments, quantitative assessments, and comprehensive investment and operational due diligence. Liquidity risk is the risk that the trust will not be able to settle liabilities such as payments to participants, counterparties, and service providers. Plan investments in limited liability pools with no active secondary market may be illiquid. Private equity funds are subject to distribution and funding schedules set by fund managers and market activity. Hedge funds may also be subject to restrictions that delay redemptions. To mitigate liquidity risk, private equity portfolios have been diversified across different vintage years and strategies, and hedge fund portfolios have been diversified across investment fund managers, strategies and liquidity provisions. In addition, the investment committee regularly reviews cash flows of the pension trusts and sets appropriate guidelines to address liquidity needs. With the change in investment strategy and a larger percentage of the plan assets invested in more liquid instruments such as publicly traded fixed income investments, liquidity risk is greatly reduced. Currency risk arises from holding plan assets denominated in a currency other than the currency in which its liabilities are settled. Currency risk is generally managed through notional contracts designed to hedge net exposure to non-functional currencies. With the change in investment strategy, currency risk will be mitigated going forward by investing more of the Canadian plan assets in Canadian dollar investments. Interest rate risk exists on both the asset and liability side, and is the risk that a change in interest rates will adversely affect the fair value of interest rate securities or liabilities, thereby affecting the overall funded status. With the change in investment strategy to more closely match the plan liabilities, interest rate risk will be greatly reduced. Credit risk is the risk that counterparties’ failure to discharge their obligations could affect cash flows. The trusts have exposure through investments in fixed income securities. This risk is mitigated by investing in a diversified portfolio. The trusts also have exposure through settlement receivables from derivative contracts. Only the amount of unsettled net receivables is at risk for these types of investments, and no principal is at risk. We decrease credit risk exposure by only dealing with highly-rated financial counterparties; as of year-end, our counterparties each had a credit rating of at least A from S&P. We further manage this risk through diversification of counterparties, predefined settlement and margining provisions and documented agreements. We are also exposed to credit risk indirectly through counterparty relationships initiated by underlying managers of investments in limited liability pools. This risk is mitigated through initial due diligence and ongoing monitoring processes. Valuation of Our Plan Assets Pension assets are stated at fair value as of the reporting date. Fair value is based on the amount that would be received to sell an asset or paid to settle a liability in an orderly transaction between market participants at the reporting date. We do not consider forced or distressed sale scenarios. 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 for 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 is: • Level 1: Inputs are unadjusted quoted prices for identical assets or 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. Investments for which fair value is measured using the net asset value per share as a practical expedient are not categorized within the fair value hierarchy. Cash and short-term investments are valued at cost, which approximates market. Fixed income investments are valued at exit prices quoted in active or non-active markets or based on observable inputs. Hedge funds, private equities, and related fund units are valued based on the net asset values of the funds. These values represent the per-unit price at which new investors are permitted to invest and existing investors are permitted to exit. When net asset values as of the end of the year have not been received, we estimate fair value by adjusting the most recently reported net asset values for market events and cash flows between the interim date and the end of the year. Derivative instruments are valued based upon valuation statements received from each derivative’s counterparty. Some of these contracts are not publicly traded. The net pension plan assets, when categorized in accordance with this fair value hierarchy, are as follows. Investments valued using net asset value (NAV) as a practical expedient are presented to reconcile with total plan assets. DOLLAR AMOUNTS IN MILLIONS 2018 LEVEL 1 LEVEL 2 LEVEL 3 NAV TOTAL Pension trust investments: Cash and short-term investments $ 275 $ 12 $ — $ — $ 287 Common and preferred stock — — — — — Fixed income investments: Corporate — 1,054 — — 1,054 Government — 426 — — 426 Hedge fund and related investments — — 3 1,811 1,814 Private equity and related investments — — 65 1,014 1,079 Derivative instruments — 15 262 — 277 Total pension trust investments 275 1,507 330 2,825 4,937 Accrued liabilities, net (17 ) Pension trust net assets 4,920 Canadian nonregistered plan assets: Cash and short-term investments 5 — — — 5 Common and preferred stock 5 — — — 5 Total Canadian nonregistered plan assets 10 — — — 10 Total plan assets $ 4,930 DOLLAR AMOUNTS IN MILLIONS 2017 LEVEL 1 LEVEL 2 LEVEL 3 NAV TOTAL Pension trust investments: Cash and short-term investments $ 580 $ 2 $ — $ — $ 582 Common and preferred stock 1 — — — 1 Hedge fund and related investments 59 — 10 3,168 3,237 Private equity and related investments — — 102 1,120 1,222 Derivative instruments — 31 445 — 476 Total pension trust investments 640 33 557 4,288 5,518 Accrued liabilities, net (16 ) Pension trust net investments 5,502 Canadian nonregistered plan assets: Cash and short-term investments 6 — — — 6 Common and preferred stock 6 — — — 6 Total Canadian nonregistered plan assets 12 — — — 12 Total plan assets $ 5,514 Assets that do not have readily available quoted prices in an active market require more judgment to value and have increased risk. Approximately $330 million , or 6.7 percent , of our pension plan assets were classified as Level 3 assets as of December 31, 2018. A reconciliation of the beginning and ending balances of the pension plan assets measured at fair value using significant unobservable inputs (Level 3) is presented below: DOLLAR AMOUNTS IN MILLIONS INVESTMENTS Hedge funds and related investments Private equity and related investments Derivative instruments, net Total Balance as of December 31, 2016 $ 4 $ 75 $ 376 $ 455 Net realized gains (losses) (1 ) (30 ) 15 (16 ) Net change in unrealized gains (losses) 2 41 67 110 Purchases — 14 — 14 Sales (1 ) — — (1 ) Settlements — — (13 ) (13 ) Transfers into Level 3 6 19 — 25 Transfers out of Level 3 — (17 ) — (17 ) Balance as of December 31, 2017 10 102 445 557 Net realized gains (losses) — — 238 238 Net change in unrealized gains (losses) 1 (5 ) (184 ) (188 ) Purchases — 5 — 5 Sales — (2 ) — (2 ) Settlements — — (237 ) (237 ) Transfers into Level 3 — 18 — 18 Transfers out of Level 3 (8 ) (53 ) — (61 ) Balance as of December 31, 2018 $ 3 $ 65 $ 262 $ 330 The availability of observable market data is monitored to assess the appropriate classification of financial instruments within the fair value hierarchy. Changes in economic conditions or model-based valuation techniques may require the transfer of financial instruments from one fair value level to another. In such instances, the transfer is reported at the beginning of the reporting period. We evaluate the significance of transfers between levels based upon the nature of the financial instrument and size of the transfer relative to total net assets available for benefits. The table below shows the fair value and aggregate notional amount of the derivative instruments held by our pension trusts at the end of the last two years. DOLLAR AMOUNTS IN MILLIONS FAIR VALUE NOTIONAL DECEMBER 31, DECEMBER 31, DECEMBER 31, DECEMBER 31, Equity and fixed income index derivatives, net $ — $ 19 $ — $ 501 Foreign currency derivatives, net — 12 13 1,413 Futures contracts, net 15 — 1,073 — Total return swaps, net 262 445 558 1,443 Total $ 277 $ 476 $ 1,644 $ 3,357 ACTUARIAL ASSUMPTIONS We use actuarial assumptions to estimate our benefit obligations and our net periodic benefit costs. The following tables show the rates used to estimate our benefit obligations and periodic net benefit costs. Rates We Use in Estimating Our Benefit Obligations PENSION DECEMBER 31, DECEMBER 31, Discount rates: United States 4.40 % 3.70 % Canada 3.70 % 3.50 % Lump sum distributions (1)(2) PPA Table PPA Table Rate of compensation increase: Salaried: United States 13.00% to 2.00% decreasing with participant age 13.00% to 2.00% decreasing with participant age Canada 3.25 % 3.25 % Hourly: United States 13.00% to 2.30% decreasing with participant age 13.00% to 2.30% decreasing with participant age Canada 3.00 % 3.00 % Lump sum or installment distributions election (2) 60.00 % 60.00 % (1) PPA Phased Table: Interest and mortality assumptions as mandated by Pension Protection Act of 2006 including the phase out of the prior interest rate basis in 2013. (2) U.S. qualified salaried and nonqualified plans only. The discount rates used for our U.S. other postretirement benefit plans were 4.20 percent and 3.50 percent for the years ended December 31, 2018 , and December 31, 2017 , respectively. Additionally, the discount rates used for our Canadian other postretirement benefit plans were 3.70 percent and 3.40 percent for the years ended December 31, 2018 , and December 31, 2017 , respectively. Estimating Our Net Periodic Benefit Costs PENSION 2018 2017 2016 Discount rates: United States 3.70 % 4.30 % 4.50 % Canada 3.50 % 3.70 % 4.00 % Lump sum distributions (1)(2) PPA Table PPA Table PPA Table Expected return on plan assets: Qualified/registered plans (3) 8.00 % 8.00 % 9.00% for all plans except 7.00% for plans assumed from Plum Creek Nonregistered plans 3.50 % 3.50 % 3.50 % Rate of compensation increase: Salaried: United States 13.00% to 2.00% decreasing with participant age 13.00% to 2.00% decreasing with participant age 13.00% to 2.00% decreasing with participant age Canada 3.25 % 3.50 % 3.50 % Hourly: United States 13.00% to 2.30% decreasing with participant age 13.00% to 2.30% decreasing with participant age 13.00% to 2.30% decreasing with participant age Canada 3.00 % 3.25 % 3.25 % Lump sum distributions election (2) 60.00 % 60.00 % 60.00 % (1) PPA Phased Table: Interest and mortality assumptions as mandated by Pension Protection Act of 2006 including the phase out of the prior interest rate basis in 2013. (2) U.S. qualified salaried and nonqualified plans only. (3) Beginning in 2017 we used an assumed expected return on plan assets of 8.00 percent for qualified and registered pension plans. The discount rates used for our U.S. other postretirement benefit plans were 3.50 percent , 3.70 percent and 4.00 percent for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , respectively. Additionally, the discount rates used for our Canadian other postretirement benefit plans were 3.40 percent , 3.60 percent and 3.90 percent for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , respectively. Expected Return on Plan Assets We estimate the expected long-term return on assets for our qualified, registered and nonregistered pension plans. Qualified and Registered Pension Plans We assumed a long-term rate of return on plan assets of 8.0 percent for the year ended December 31, 2018 . As of the end of 2018, we have begun implementing a change in our asset strategy to an allocation that will more closely match the plan’s liability profile moving forward, resulting in a larger allocation of our assets into fixed income securities. With this change, we have determined that we will reduce our assumption of long-term rate of return on plan assets to 7.0 percent for the year ended December 31, 2019 . Determining our expected return requires a high degree of judgment. We consider actual pension fund performance over multiple years, and current and expected valuation levels in the global equity and credit markets. Historical fund returns are used as a base, and we place added weight on more recent pension plan asset performance. Nonregistered Plans Canadian tax rules require that 50 percent of the assets for nonregistered plans go to a noninterest-bearing refundable tax account. As a result, the return we earn investing the other 50 percent is spread over 100 percent of the assets. Our expected long-term annual rate of return on the portion we are allowed to manage is 7.0 percent . This assumption is based on historical experience and future return expectations. The expected overall annual return on assets that fund our nonregistered plans is 3.5 percent. Health Care Costs Rising costs of health care affect the costs of our other postretirement plans. We use assumptions about health care cost trend rates to estimate the cost of benefits we provide. Our trend rate assumptions are based on historical market experience, current environment and future expectations. In 2018 , the assumed weighted health care cost trend rate was: • 8.4 percent for U.S. Pre-Medicare • 4.5 percent for U.S. Health Reimbursement Account (HRA) • 5.1 percent for Canada This table shows the assumptions we use in estimating the annual cost increase for health care benefits we provide. Assumptions We Use in Estimating Health Care Benefit Cost Trends 2018 2017 U.S. CANADA U.S. CANADA Weighted health care cost trend rate assumed for next year 7.80% for Pre-Medicare and 4.50% for HRA 4.90 % 8.40% for Pre-Medicare and 4.50% for HRA 5.10 % Rate that the cost trend rate gradually declines to 4.50 % 4.00 % 4.50 % 4.30 % Year the cost trend rate is reached 2037 2039 2037 2028 The assumed health care cost trend rate can influence projected postretirement benefit plan payments. The following table demonstrates the effect a one percent change in assumed health care cost trend rates would have with all other assumptions remaining constant. Effect of a One Percent Change in Health Care Costs AS OF DECEMBER 31, 2018 (DOLLAR AMOUNTS IN MILLIONS) 1% INCREASE 1% DECREASE Effect on total service and interest cost components Less than $1 Less than $(1) Effect on accumulated postretirement benefit obligation $ 5 $ (4 ) ACTIVITY OF PLANS Net Periodic Benefit Cost (Credit) DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS 2018 2017 2016 2018 2017 2016 Net periodic benefit cost (credit): Service cost (1) $ 37 $ 35 $ 48 $ — $ — $ — Interest cost 236 264 277 7 8 8 Expected return on plan assets (399 ) (409 ) (495 ) — — — Amortization of actuarial loss 225 195 156 8 8 9 Amortization of prior service cost (credit) 3 4 4 (8 ) (8 ) (7 ) Accelerated pension costs for Plum Creek merger-related change-in-control provisions — — 5 — — — Settlement charge 200 — — — — — Net periodic benefit cost (credit) $ 302 $ 89 $ (5 ) $ 7 $ 8 $ 10 (1) Service cost includes $13 million in 2016 for employees that were part of our Cellulose Fibers divestitures. These charges are included in our results of discontinued operations. Curtailment and special termination benefits are related to involuntary terminations due to restructuring activities. Estimated Amortization from Accumulated Other Comprehensive Loss in 2019 DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS TOTAL Net actuarial loss $ 108 $ 7 $ 115 Prior service cost (credit) 4 (1 ) 3 Net effect cost $ 112 $ 6 $ 118 Expected Pension Plan and Benefit Funding Established funding standards govern the funding requirements for our qualified and registered pension plans. We fund the benefit payments of our nonqualified and nonregistered plans as benefit payments come due. We voluntarily contributed $300 million to our U.S. qualified pension plans during 2018, although there was no minimum required contribution for the year . During 2018 , we contributed $22 million for our Canadian registered plans, we made contributions and benefit payments of $2 million for our Canadian nonregistered pension plans and made benefit payments of $19 million for our nonqualified pension plans. During 2019 , based on estimated year-end asset values and projections of plan liabilities, we expect to: • be required to contribute approximately $17 million for our Canadian registered plan; • be required to contribute or make benefit payments for our Canadian nonregistered plans of $3 million ; and • make benefit payments of approximately $16 million for our U.S. nonqualified pension plans. We do not anticipate a contribution being required for our U.S. qualified pension plan for 2019 . Expected Postretirement Benefit Funding Benefits for these plans are paid from our general assets as they come due. We expect to make benefit payments of $23 million for our U.S. and Canadian other postretirement benefit plans in 2019 , including $6 million expected to be required to cover benefit payments under collectively bargained contractual obligations. Estimated Projected Benefit Payments for the Next 10 Years DOLLAR AMOUNTS IN MILLIONS PENSION (1) OTHER POSTRETIREMENT BENEFITS 2019 $ 272 $ 17 2020 233 16 2021 231 15 2022 232 14 2023 234 14 2024-2028 1,161 57 (1) Estimated payments exclude future payments transferred in conjunction with our January 2019 group annuity contract purchase. UNION-ADMINISTERED MULTIEMPLOYER BENEFIT PLANS We contribute to multiemployer defined benefit plans under the terms of collective-bargaining agreements. These plans cover a small number of our employees and on an annual basis our contributions are immaterial. These plans have different risks than single-employer plans. Our contributions may be used to fund benefits for employees of other participating employers. If we choose to stop participating, we may be required to pay a withdrawal liability based on the underfunded status of the plan . If another participating employer stops contributing to the plan, we may become responsible for remaining plan unfunded obligations. DEFINED CONTRIBUTION PLANS We sponsor various defined contribution plans for our U.S. and Canadian salaried and hourly employees. Our contributions to these plans were: • $22 million in 2018 , • $21 million in 2017 and • $27 million in 2016 .

ACCRUED LIABILITIES

ACCRUED LIABILITIES	12 Months Ended
	Dec. 31, 2018
ACCRUED LIABILITIES	ACCRUED LIABILITIES Accrued liabilities were comprised of the following: DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Accrued compensation and employee benefit costs $ 192 $ 223 Accrued taxes payable 30 43 Customer rebates, volume discounts and deferred income 99 96 Interest 109 111 Product remediation accrual (Note 19) 2 98 Other 58 74 Total $ 490 $ 645

LINES OF CREDIT

LINES OF CREDIT	12 Months Ended
	Dec. 31, 2018
Line of Credit Facility [Line Items]
LINES OF CREDIT	LINES OF CREDIT OUR LINES OF CREDIT During March 2017 , we entered into a $1.5 billion five-year senior unsecured revolving credit facility that expires in March 2022 . This replaced a $1 billion senior unsecured revolving credit facility that was originally set to expire September 2018 . Borrowings are at LIBOR plus a spread or at other interest rates mutually agreed upon between the borrower and the lending banks. As of December 31, 2018 , we had $425 million of outstanding borrowings on the revolving credit facility and had an additional $1,075 million available. We were in compliance with the revolving credit facility covenants as of December 31, 2018 . OTHER LETTERS OF CREDIT AND SURETY BONDS The amounts of other letters of credit and surety bonds we have entered into as of the end of our last two years are included in the following table: DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Letters of credit $ 38 $ 37 Surety bonds $ 123 $ 134 Our compensating balance requirements for our letters of credit were $6 million as of December 31, 2018 .

LONG-TERM DEBT

LONG-TERM DEBT	12 Months Ended
	Dec. 31, 2018
Long-term Debt, by Current and Noncurrent [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT This note provides details about: • term loans issued and extinguished and • long-term debt and long-term debt maturities. Our long-term debt includes notes, debentures and other borrowings. TERM LOANS ISSUED AND EXTINGUISHED During February 2018, we paid our $ 62 million 7.00 percent debenture at maturity. During July 2017 , we prepaid a $550 million variable-rate term loan originally set to mature in 2020 (2020 term loan). The 2020 term loan was prepaid using available cash of $325 million as well as borrowing proceeds from a new $225 million variable-rate term loan set to mature in 2026 (2026 term loan). The 2020 term loan was eligible to receive patronage refunds while outstanding. Similarly, we receive patronage refunds on the 2026 term loan, which will continue while the loan remains outstanding. LONG-TERM DEBT AND LONG-TERM DEBT MATURITIES The following table lists our long-term debt by types and interest rates at the end of our last two years and includes the current portion. Long-Term Debt by Types and Interest Rates (Includes Current Portion) DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, 7.00% debentures due 2018 — 62 7.375% notes due 2019 500 500 9.00% debentures due 2021 150 150 4.70% debentures due 2021 588 597 7.125% debentures due 2023 191 191 5.207% debentures due 2023 881 885 4.625% notes due 2023 500 500 3.25% debentures due 2023 324 324 8.50% debentures due 2025 300 300 7.95% debentures due 2025 136 136 7.70% debentures due 2026 150 150 7.35% debentures due 2026 62 62 7.85% debentures due 2026 100 100 Variable rate term loan credit facility matures 2026 225 225 6.95% debentures due 2027 300 300 7.375% debentures due 2032 1,250 1,250 6.875% debentures due 2033 275 275 Other 1 1 5,933 6,008 Less unamortized discounts (5 ) (5 ) Less unamortized debt expense (9 ) (11 ) Total $ 5,919 $ 5,992 Portion due within one year $ 500 $ 62 Amounts of Long-Term Debt Due Annually for the Next Five Years and the Total Amount Due After 2023 DOLLAR AMOUNTS IN MILLIONS (1) 2019 $ 500 2020 — 2021 719 2022 — 2023 1,876 Thereafter 2,798 (1) Excludes $26 million of unamortized discounts, capitalized debt expense and fair value adjustments (related to Plum Creek merger).

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
FAIR VALUE OF FINANCIAL INSTRUMENTS	FAIR VALUE OF FINANCIAL INSTRUMENTS FAIR VALUE OF DEBT The estimated fair values and carrying values of our long-term debt and line of credit consisted of the following: DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, 2018 DECEMBER 31, 2017 CARRYING VALUE FAIR VALUE (LEVEL 2) CARRYING VALUE FAIR VALUE (LEVEL 2) Long-term debt (including current maturities) and line of credit: Fixed rate $ 5,694 $ 6,345 $ 5,768 $ 6,823 Variable rate 650 650 224 225 Total Debt $ 6,344 $ 6,995 $ 5,992 $ 7,048 To estimate the fair value of long-term debt, we used the market approach, which is based on quoted market prices we received for the same types and issues of our debt. We believe that our variable rate long-term debt and line of credit 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.

LEGAL PROCEEDINGS, COMMITMENTS

LEGAL PROCEEDINGS, COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2018
LEGAL PROCEEDINGS, COMMITMENTS AND CONTINGENCIES	LEGAL PROCEEDINGS, COMMITMENTS AND CONTINGENCIES This note provides details about our: • legal proceedings, • environmental matters and • commitments and other contingencies. LEGAL PROCEEDINGS We are party to various legal proceedings arising in the ordinary course of business. We are not currently a party to any legal proceeding that management believes could have a material adverse effect on our Consolidated Balance Sheet, Consolidated Statement of Operations , or Consolidated Statement of Cash Flows . See Note 21: Income Taxes for a discussion of a tax proceeding involving Plum Creek's 2008 U.S. federal income tax return. ENVIRONMENTAL MATTERS Site Remediation Under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) – commonly known as Superfund – and similar state laws, we: • are a party to various proceedings related to the cleanup of hazardous waste sites and • have been notified that we may be a potentially responsible party related to the cleanup of other hazardous waste sites for which proceedings have not yet been initiated. We have received notification from the Environmental Protection Agency (the EPA) and have acknowledged that we are a potentially responsible party in a portion of the Kalamazoo River Superfund site in southwest Michigan. Our involvement in the remediation site is based on our former ownership of the Plainwell, Michigan mill located within the remediation site. Several other companies also have been deemed potentially responsible parties as past or present owners or operators of facilities within the site, or as arrangers under CERCLA. We cooperated with other parties to jointly implement an administrative order issued by the EPA on April 14, 2016, with respect to a portion of the site comprising a stretch of the river approximately 1.7 miles long referred to as the Otsego Township Dam Area. During third quarter 2018, implementation of this administrative order was completed. In 2010, the company, along with others, was named as a defendant by Georgia-Pacific Consumer Products LP, Fort James Corporation and Georgia-Pacific LLC in an action seeking contribution under CERCLA for remediation costs relating to a certain area within the site. On March 29, 2018, the U.S. District Court issued an opinion and order assigning the company responsibility for 5 percent of approximately $50 million in past costs incurred by the plaintiffs. The remaining 95 percent of this pool of past costs incurred was allocated to the plaintiffs and other defendants. The opinion and order, which is currently on appeal before the US Court of Appeals for the Sixth Circuit, does not establish allocation for future remediation costs, and accordingly, we may incur additional costs in connection with future remediation tasks for other areas of the site. In connection with the opinion and order, we updated our best estimate of the liability associated with the site and recorded a pretax charge of $28 million in first quarter 2018 within "Other operating costs (income), net" on the Consolidated Statement of Operations . Our Established Reserves. We have established reserves for estimated remediation costs on the active Superfund sites and other sites for which we are a potentially responsible party. These reserves are recorded in "Accrued liabilities" and "Other liabilities" in our Consolidated Balance Sheet . Changes in the Reserve for Environmental Remediation DOLLAR AMOUNTS IN MILLIONS Reserve balance as of December 31, 2017 $ 48 Reserve charges and adjustments, net 27 Payments (13 ) Reserve balance as of December 31, 2018 $ 62 We change our accrual to reflect: • new information on any site concerning implementation of remediation alternatives, • updates on prior cost estimates and new sites and • costs incurred to remediate sites. 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 $126 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. We have not recorded any amounts for potential recoveries from insurance carriers. Asset Retirement Obligations We have obligations associated with the retirement of tangible long-lived assets consisting primarily of reforestation obligations related to forest management licenses in Canada and obligations to close and cap landfills. Some of our sites have asbestos containing materials. We have met our current legal obligation to identify and manage these materials. In situations where we cannot reasonably determine when asbestos containing materials might be removed from the sites, we have not recorded an accrual because the fair value of the obligation cannot be reasonably estimated. These obligations are recorded in "Accrued liabilities" and "Other liabilities" in our Consolidated Balance Sheet . Changes in the Reserve for Asset Retirement Obligations DOLLAR AMOUNTS IN MILLIONS Reserve balance as of December 31, 2017 $ 32 Reserve charges and adjustments, net 11 Payments (12 ) Other adjustments (1) (2 ) Reserve balance as of December 31, 2018 $ 29 (1) Primarily related to a foreign currency remeasurement gain for our Canadian reforestation obligation. COMMITMENTS AND OTHER CONTINGENCIES Our commitments and contingencies include: • guarantees of debt and performance, • operating leases and • product remediation contingency. Guarantees We have guaranteed the performance of the buyer of a timberland contract we sold in 2005. Future payments on the contract, which expires in 2023 , are $10 million . Operating Leases Our rent expense was: • $47 million in 2018 , • $39 million in 2017 and • $37 million in 2016 (excluding discontinued operations). We have operating leases for: • various equipment, including logging equipment, lift trucks, automobiles and office equipment and • office and warehouse space. Future Commitments on Operating Leases Our operating lease commitments as of December 31, 2018 were: DOLLAR AMOUNTS IN MILLIONS 2019 $ 35 2020 29 2021 26 2022 24 2023 18 Thereafter 78 Product Remediation Contingency Refer to Note 19: Charges (Recoveries) for Product Remediation, Net for further information.

SHAREHOLDERS' INTEREST

SHAREHOLDERS' INTEREST	12 Months Ended
	Dec. 31, 2018
SHAREHOLDERS' INTEREST	SHAREHOLDERS’ INTEREST This note provides details about: • preferred and preference shares, • common shares, • share-repurchase programs and • accumulated other comprehensive loss PREFERRED AND PREFERENCE SHARES We had no preferred shares outstanding at the end of 2018 or 2017 . We have authorization to issue 7 million preferred shares with a par value of $1.00 per share. On June 24, 2013, we issued 13.8 million of our 6.375 percent Mandatory Convertible Preference Shares, Series A, par value $1.00 and liquidation preference of $50.00 per share, for net proceeds of $669 million . On July 1, 2016, all outstanding 6.375 percent Mandatory Convertible Preference Shares, Series A (Preference Shares) converted into Weyerhaeuser common shares at a rate of 1.6929 Weyerhaeuser common shares per Preference Share. The company issued a total of 23.2 million Weyerhaeuser common shares in conjunction with the conversion, based on 13.7 million Preference Shares outstanding as of the conversion date. In accordance with the terms of the Preference Shares, the number of Weyerhaeuser common shares issuable on conversion was determined based on the average volume weighted average price of $29.54 for Weyerhaeuser common shares over the 20-trading-day period beginning June 1, 2016, and ending on June 28, 2016. COMMON SHARES The number of common shares we have outstanding changes when: • new shares are issued, • stock options are exercised, • restricted stock units or performance share units vest, • stock-equivalent units are paid out, • shares are tendered, • shares are repurchased or • shares are canceled. Reconciliation of Our Common Share Activity SHARES IN THOUSANDS 2018 2017 2016 Outstanding at beginning of year 755,223 748,528 510,483 Issuance from merger with Plum Creek (Note 5) — — 278,887 Stock options exercised 2,026 5,970 2,571 Issued for restricted stock units 466 605 840 Issued for performance shares 86 120 219 Preference shares converted to common — — 23,345 Repurchased (11,410 ) — (67,817 ) Outstanding at end of year 746,391 755,223 748,528 SHARE REPURCHASE PROGRAMS In November 2015, our board of directors approved a share repurchase program under which we were authorized to repurchase up to $2.5 billion of outstanding shares subsequent to the closing of our merger with Plum Creek (the 2016 Repurchase Program). Transaction fees incurred for repurchases are not counted as use of funds authorized for repurchases under the 2016 Share Repurchase Authorization. During 2016, we repurchased 68 million shares of common stock for $2 billion under the 2016 Repurchase Program. We did not repurchase any shares of common stock during 2017. As of December 31, 2017 , we had remaining authorization of $500 million for future stock repurchases. During 2018, we repurchased 11 million shares of common stock for $366 million (including transaction fees), under the 2016 Repurchase Program. As of December 31, 2018 , we had remaining authorization of $135 million for future stock repurchases. On February 7, 2019, our board of directors terminated the 2016 Repurchase Program and approved a new share repurchase program (the 2019 Repurchase Program) under which we are authorized to repurchase up to $500 million of outstanding shares. All common stock purchases under the 2016 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. There were no unsettled repurchases as of December 31, 2018 , or December 31, 2017 . ACCUMULATED OTHER COMPREHENSIVE LOSS Changes in amounts included in our accumulated other comprehensive loss by component are: DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS Foreign currency translation adjustments Actuarial loss Prior service cost Actuarial loss Prior service credit Unrealized gains on available-for-sale securities Total Ending balance as of December 31, 2016 $ 232 $ (1,651 ) $ (9 ) $ (67 ) $ 29 $ 7 $ (1,459 ) Other comprehensive income (loss) before reclassifications (1) 32 (280 ) (2 ) 14 — 2 (234 ) Amounts reclassified from accumulated other comprehensive income (loss) to earnings (1)(2) — 129 3 5 (6 ) — 131 Total other comprehensive income (loss) 32 (151 ) 1 19 (6 ) 2 (103 ) Ending balance as of December 31, 2017 264 (1,802 ) (8 ) (48 ) 23 9 (1,562 ) Other comprehensive income (loss) before reclassifications (1) (54 ) 393 (5 ) 12 1 — 347 Amounts reclassified from accumulated other comprehensive income (loss) to earnings (1)(2)(3) — 322 3 6 (6 ) — 325 Total other comprehensive income (loss) (54 ) 715 (2 ) 18 (5 ) — 672 Reclassification of certain tax effects due to tax law changes (4) — (245 ) (1 ) (12 ) 5 — (253 ) Reclassification of accumulated unrealized gains on available-for-sale securities (5) — — — — — (9 ) (9 ) Net amounts reclassified from accumulated other comprehensive loss to retained earnings — (245 ) (1 ) (12 ) 5 (9 ) (262 ) Ending balance as of December 31, 2018 210 (1,332 ) (11 ) (42 ) 23 — (1,152 ) (1) Amounts are presented net of tax. (2) Amounts of actuarial loss and prior service (cost) credit are components of net periodic benefit cost (credit). See Note: 10: Pension and Other Postretirement Benefit Plans . (3) Amounts include a settlement charge totaling $200 million related to our U.S. qualified pension plan for the year ended December 31, 2018. See Note: 10: Pension and Other Postretirement Benefit Plan s for further detail. (4) We reclassified certain tax effects from tax law changes of $253 million from "Accumulated other comprehensive loss" to "Retained earnings" on our Consolidated Balance Sheet in accordance with ASU 2018-02. See Note 1: Summary of Significant Accounting Policies . (5) We reclassified accumulated unrealized gains from available-for-sale securities of $9 million from "Accumulated other comprehensive loss" to "Retained earnings" on our Consolidated Balance Sheet in accordance with ASU 2016-01. See Note 1: Summary of Significant Accounting Policies .

SHARE-BASED COMPENSATION

SHARE-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2018
SHARE-BASED COMPENSATION	SHARE-BASED COMPENSATION This note provides details about: • our Long-Term Incentive Compensation Plan (2013 Plan), • share-based compensation resulting from our merger with Plum Creek, • how we account for share-based awards, • tax benefits of share-based awards, • types of share-based compensation, • unrecognized share-based compensation and • deferred compensation stock equivalent units. Share-based compensation expense was: • $42 million in 2018 , • $40 million in 2017 and • $60 million in 2016 . The 2016 amount above contains a $6 million award to employees of the divested Cellulose Fibers businesses which is included in our results of discontinued operations. OUR LONG-TERM INCENTIVE COMPENSATION PLAN Our long-term incentive plans provide for share-based awards that include: • restricted stock, • restricted stock units (RSUs), • performance shares, • performance share units (PSUs), • stock options and • stock appreciation rights (SARs). We may issue future grants of up to 21 million shares under the 2013 Plan. We also have the right to reissue forfeited and expired grants. For restricted stock, RSUs, performance shares, PSUs or other equity grants: • An individual participant may receive a grant of up to 1 million shares annually. • No participant may be granted awards that exceed $10 million earned in a 12-month period. For stock options and SARs: • An individual participant may receive a grant of up to 2 million shares in any one calendar year. • The exercise price is required to be the market price on the date of the grant. We have not granted any additional SARs since 2016. Additionally, the remaining liability related to SARs is immaterial at December 31, 2018. The Compensation Committee of our board of directors annually establishes an overall pool of stock awards available for grants based on performance. For stock-settled awards, we: • issue new stock into the marketplace and • generally do not repurchase shares in connection with issuing new awards. Our common shares would increase by approximately 30 million shares if all share-based awards were exercised or vested. These include: • all options, RSUs and PSUs outstanding at December 31, 2018 , under the 2013 Plan and 2004 Plan; and • all remaining options, RSUs and PSUs that could be granted under the 2013 Plan. SHARE-BASED COMPENSATION RESULTING FROM OUR MERGER WITH PLUM CREEK Replacement awards were granted as a result of the merger with Plum Creek. Eligible outstanding Plum Creek stock options, RSUs and deferred stock unit awards were converted into equivalent equity awards with respect to Weyerhaeuser Common Shares, after giving effect to the appropriate adjustments to reflect the consummation of the merger. In total, we issued replacement awards consisting of 1,953 thousand stock options and 1,248 thousand RSUs. The replacement stock option awards were fully vested and had a total value of $5 million , which was included in the equity consideration issued with the merger. Qualifying terminations during 2016 resulted in accelerated vesting of 705 thousand of the replacement RSUs and recognition of $15 million of expense. The accelerated expense is included in the merger-related integration costs as described in Note 18: Charges for Integration and Restructuring, Closures and Asset Impairments . We also assumed 289,910 value management awards (VMAs) through the merger with Plum Creek. Qualifying terminations during 2016 resulted in $6 million of expense recognized for VMAs. This accelerated expense is included in merger-related integration costs as described in Note 18: Charges for Integration and Restructuring, Closures and Asset Impairments . 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. TAX BENEFITS OF SHARE-BASED AWARDS Our total income tax benefit from share-based awards — as recognized in our Consolidated Statement of Operations — for the last three years was: • $5 million in 2018 , • $6 million in 2017 and • $12 million in 2016 . The 2016 amount above contains a $2 million income tax benefit from share-based awards to employees that were part of the Cellulose Fibers divestitures which is included in our results of discontinued operations. Tax benefits from share-based awards are accrued as stock compensation expense and realized when: • restricted shares and RSUs vest, • performance shares and PSUs vest, • stock options are exercised and • SARs are exercised. TYPES OF SHARE-BASED COMPENSATION Our share-based compensation is in the form of: • restricted stock units, • performance share units, • stock options and • stock appreciation rights. RESTRICTED STOCK UNITS Through the 2013 Plan, we award RSUs — grants that entitle the holder to shares of our stock as the award vests. The Details Our RSUs granted in 2018 , 2017 and 2016 generally: • vest ratably over four years; • immediately vest in the event of death while employed or disability; • continue to vest upon retirement at an age of at least 62, but a portion of the grant is forfeited if retirement occurs before the one year anniversary of the grant; • continue vesting for one year in the event of involuntary termination when the retirement has not been met; and • will be forfeited upon termination of employment in all other situations including early retirement prior to age 62. Our Accounting The fair value of our RSUs is the market price of our stock on the grant-date of the awards. We generally record share-based compensation expense for RSUs over the four-year vesting period. Generally, for RSUs that continue to vest following the termination of employment, we record the share-based compensation expense over a required service period that is less than the stated vesting period. Activity The following table shows our RSU activity for 2018 . RESTRICTED STOCK UNITS (IN THOUSANDS) WEIGHTED AVERAGE GRANT-DATE FAIR VALUE Nonvested at December 31, 2017 1,515 $ 29.12 Granted 710 34.19 Vested (560 ) 28.81 Forfeited (72 ) $ 30.19 Nonvested at December 31, 2018 (1) 1,593 $ 31.41 (1) As of December 31, 2018, there were approximately 336 thousand RSUs that had met the requisite service period and will be released as identified in the grant terms. The weighted average grant-date fair value for RSUs was: • $34.19 in 2018 , • $32.83 in 2017 and • $30.25 in 2016 . The total grant-date fair value of RSUs vested was: • $16 million in 2018 , • $18 million in 2017 and • $36 million in 2016 . Nonvested RSUs accrue dividends that are paid out when RSUs vest. Any RSUs forfeited will not receive dividends. As RSUs vest, a portion of the shares awarded is withheld to cover employee taxes. As a result, the number of stock units vested and the number of common shares issued will differ. PERFORMANCE SHARE UNITS Through the 2013 Plan, we award PSUs — grants that entitle the holder to shares of our stock as the award vests. The Details The final number of shares awarded will range from 0 percent to 150 percent of each grant’s target, depending upon actual company performance. For shares granted in 2018 and 2017, the ultimate number of PSUs earned is based on two measures: • our relative total shareholder return (TSR) ranking measured against the S&P 500 over a three-year period and • our relative TSR ranking measured against an industry peer group of companies over a three-year period. For shares granted in 2016, the ultimate number of PSUs earned is based on three measures: • our relative total shareholder return (TSR) ranking measured against the S&P 500 over a three-year period, • our relative TSR ranking measured against an industry peer group of companies over a three-year period and • achievement of Plum Creek merger cost synergy targets. The vesting provisions for PSUs granted in 2018, 2017, and 2016 were as follows: • vest 100 percent on the third anniversary of the grant date as long as the individual remains employed by the company; • fully vest in the event the participant dies or becomes disabled while employed; • continue to vest upon retirement at an age of at least 62, but a portion of the grant is forfeited if retirement occurs before the one year anniversary of the grant; • continue vesting for one year in the event of involuntary termination when the retirement criteria has not been met and the employee has met the second anniversary of the grant date; and • will be forfeited upon termination of employment in all other situations including early retirement prior to age 62. Our Accounting Since the awards contain a market condition, the effect of the market condition is reflected in the grant-date fair value which is estimated using a Monte Carlo simulation model. This model estimates the TSR ranking of the company over the performance period. Compensation expense is based on the estimated probable number of earned awards and recognized over the vesting period on an accelerated basis. Generally, compensation expense would be reversed if the performance condition is not met unless the requisite service period has been achieved. Weighted Average Assumptions Used in Estimating the Value of Performance Share Units 2018 2017 2016 Performance period 1/1/2018-12/31/2020 1/1/2017 – 12/31/2019 1/1/2016 – 12/31/2018 Expected dividends 3.81% 3.74% 3.92% - 5.37% Risk-free rate 1.75% - 2.34% 0.68% - 1.55% 0.45% - 0.97% Volatility 17.30% - 21.52% 22.71% - 24.07% 21.87% - 28.09% Weighted average grant-date fair value $ 35.49 $ 37.93 $ 22.58 Activity The following table shows our PSU activity for 2018 . GRANTS (IN THOUSANDS) WEIGHTED AVERAGE GRANT-DATE FAIR VALUE Nonvested at December 31, 2017 965 $ 30.87 Granted at target 343 35.49 Vested (112 ) 32.79 Forfeited (26 ) 37.93 Performance adjustment (128 ) $ 34.74 Nonvested at December 31, 2018 (1) 1,042 $ 31.52 (1) As of December 31, 2018, there were approximately 232 thousand PSUs that had met the requisite service period and will be released as identified in the grant terms. The total grant-date fair value of PSUs vested was: • $4 million in 2018 , • $4 million in 2017 and • $8 million in 2016 . As PSUs vest, a portion of the shares awarded is withheld to cover participant taxes. As a result, the number of stock units vested and the number of common shares issued will differ. STOCK OPTIONS Stock options entitle award recipients to purchase shares of our common stock at a fixed exercise price. During 2018 and 2017, we did not grant any stock option awards. When granted in prior years, however, we granted stock options with an exercise price equal to the market price of our stock on the date of the grant. The Details Our stock options generally: • vest over four years of continuous service, • must be exercised within 10 years of the grant-date and • use a Black-Scholes option valuation model to estimate the fair value of every stock option award on its grant-date. Activity The following table shows our option unit activity for 2018 . OPTIONS (IN THOUSANDS) WEIGHTED AVERAGE EXERCISE PRICE WEIGHTED AVERAGE REMAINING CONTRACTUAL TERM (IN YEARS) AGGREGATE INTRINSIC VALUE (IN MILLIONS) Outstanding at December 31, 2017 8,487 $ 26.47 Exercised (2,025 ) $ 25.68 Forfeited or expired (96 ) $ 25.02 Outstanding at December 31, 2018 (1) 6,366 $ 26.75 5.33 $ 4 Exercisable at December 31, 2018 4,732 $ 27.14 4.78 $ 4 (1) As of December 31, 2018, there were approximately 573 thousand stock options that had met the requisite service period and will be released as identified in the grant terms. The total intrinsic value of stock options exercised was: • $22 million in 2018 , • $68 million in 2017 and • $18 million in 2016 . UNRECOGNIZED SHARE-BASED COMPENSATION As of December 31, 2018 , our unrecognized share-based compensation cost for all types of share-based awards included $33 million related to non-vested equity-classified share-based compensation arrangements — expected to be recognized over a weighted average period of approximately 1.1 years . DEFERRED COMPENSATION STOCK EQUIVALENT UNITS Certain employees and our board of directors may defer compensation into stock-equivalent units. The Details The 2013 Plan works differently for employees and directors. Eligible employees: • may choose to defer all or part of their bonus into stock-equivalent units; • may choose to defer part of their salary, except for executive officers; and • receive a 15 percent premium if the deferral is for at least five years. Our directors: • receive a portion of their annual retainer fee in the form of RSUs, which vest over one year and may be deferred into stock-equivalent units; • may choose to defer some or all of the remainder of their annual retainer fee into stock-equivalent units; and • do not receive a premium for their deferrals. Employees and directors also choose when the deferrals will be paid out although no deferrals may be paid until after the separation from service of the employee or director. Our Accounting We settle all deferred compensation accounts in cash for our employees. Our directors receive shares of common stock as payment for stock-equivalent units. In addition, we credit all stock-equivalent accounts with dividend equivalents. The number of common shares to be issued in the future to directors is 639 thousand . Stock-equivalent units are: • liability-classified awards and • re-measured to fair value at every reporting date. The fair value of a stock-equivalent unit is equal to the market price of our stock. Activity The number of stock-equivalent units outstanding in our deferred compensation accounts were: • 788 thousand as of December 31, 2018 , • 804 thousand as of December 31, 2017 and • 1,004 thousand as of December 31, 2016 .

CHARGES FOR INTEGRATION AND RES

CHARGES FOR INTEGRATION AND RESTRUCTURING, CLOSURES AND ASSET IMPAIRMENTS	12 Months Ended
	Dec. 31, 2018
CHARGES FOR INTEGRATION AND RESTRUCTURING, CLOSURES AND ASSET IMPAIRMENTS	CHARGES FOR INTEGRATION AND RESTRUCTURING, CLOSURES AND ASSET IMPAIRMENTS Items Included in Our Charges for Integration and Restructuring, Closures and Asset Impairments DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Integration and restructuring charges related to our merger with Plum Creek: Termination benefits $ — $ 11 $ 54 Acceleration of share-based compensation related to qualifying terminations (Note 17) — — 21 Acceleration of pension benefits related to qualifying terminations (Note 10) — — 5 Professional services — 16 52 Other integration and restructuring costs — 7 14 Total integration and restructuring charges related to our merger with Plum Creek — 34 146 Charges related to closures and other restructuring activities 1 6 8 Impairment of long-lived assets 1 154 16 Total charges for integration and restructuring, closures and asset impairments $ 2 $ 194 $ 170 INTEGRATION, RESTRUCTURING AND CLOSURES During 2017, we incurred and accrued for termination benefits (primarily severance) and non-recurring professional services costs directly attributable to our merger with Plum Creek. During 2016, we incurred and accrued for termination benefits (primarily severance), accelerated share-based payment costs, and accelerated pension benefits based upon actual and expected qualifying terminations of certain employees as a result of restructuring decisions made subsequent to the merger. We also incurred non-recurring professional services costs for investment banking, legal and consulting, and certain other fees directly attributable to our merger with Plum Creek. Other restructuring and closure costs include lease termination charges, dismantling and demolition of plant and equipment, gain or loss on disposition of assets, environmental cleanup costs and incremental costs to wind down operating facilities. ASSET IMPAIRMENTS The Impairment of Long-Lived Assets section of Note 1: Summary of Significant Accounting Policies provides details about how we account for these impairments. Additional information can also be found in our Critical Accounting Policies . Long-Lived Assets Our long-lived asset impairments were primarily related to the following: • 2017 — In second quarter 2017, we recognized an impairment charge to the timberlands and manufacturing assets of our Uruguayan operations. On June 2, 2017, our Board of Directors approved an agreement to sell all of the Company's equity in the Uruguayan operations to a consortium led by BTG Pactual's Timberland Investment Group (TIG). As a result of this agreement, the related assets met the criteria to be classified as held for sale at June 30, 2017. This designation required us to record the related assets at fair value, less an amount of estimated selling costs, and thus recognize a $147 million noncash pretax impairment charge. This amount was recorded in the Timberlands segment. The fair value of the related assets was primarily based on the agreed upon cash purchase price of $403 million . On September 1, 2017, we announced the completion of the sale. Refer to Note 4: Discontinued Operations and Other Divestitures for further details on the Uruguayan operations sale. Additionally, in September 2017, we recognized an impairment charge of $6 million related to a nonstrategic asset in our Wood Products segment. The fair value of the asset was determined using the value indicated in a purchase and sale agreement. • 2016 — We recognized a $15 million impairment charge in Real Estate & ENR which represents the fair value less direct selling costs of certain development projects that we planned to sell that had a book value greater than fair value. The fair values of the projects were determined using significant unobservable inputs (Level 3) based on broker opinion of value reports.

CHARGES (RECOVERIES) FOR PRODUC

CHARGES (RECOVERIES) FOR PRODUCT REMEDIATION, NET (Notes)	12 Months Ended
	Dec. 31, 2018
CHARGES (RECOVERIES) FOR PRODUCT REMEDIATION, NET	CHARGES (RECOVERIES) FOR PRODUCT REMEDIATION, NET In July 2017, we announced the implementation of a solution to address concerns regarding our TJI® Joists coated with our former Flak Jacket® Protection product. This issue was isolated to Flak Jacket product manufactured after December 1, 2016, and did not affect any of our other products. We recorded insurance recoveries of $25 million and product remediation charges of $25 million for the year ended December 31, 2018 . During the year ended December 31, 2017 , we recorded $290 million to accrue for expected costs associated with the remediation. The charges recorded were attributable to our Wood Products segment and were recorded in "Charges (recoveries) for product remediation, net" on the Consolidated Statement of Operations .

OTHER OPERATING COSTS (INCOME),

OTHER OPERATING COSTS (INCOME), NET	12 Months Ended
	Dec. 31, 2018
OTHER OPERATING COSTS (INCOME), NET	OTHER OPERATING COSTS (INCOME), NET Other operating costs (income), net: • includes both recurring and occasional income and expense items and • can fluctuate from year to year. Various Income and Expense Items Included in Other Operating Costs (Income), Net DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Gain on disposition of nonstrategic assets (1) $ (5 ) $ (16 ) $ (60 ) Foreign exchange losses (gains), net (2) (3 ) (1 ) (6 ) Litigation expense, net 35 20 24 Gain on sale of timberlands (3) — (99 ) — Environmental remediation insurance recoveries (5 ) (42 ) — Other, net (4) 52 10 (11 ) Total other operating costs (income), net $ 74 $ (128 ) $ (53 ) (1) Gain on disposition of nonstrategic assets in 2016 included a $36 million pretax gain recognized in first quarter 2016 on the sale of our Federal Way, Washington headquarters campus. (2) Foreign exchange gains and losses result from changes in exchange rates primarily related to our U.S. dollar denominated cash and debt balances that are held by our Canadian subsidiary. (3) Gain on sale of 100,000 acres sold to Twin Creeks during Q4 2017. Refer to Note 9: Related Parties for further information. (4) "Other, net" includes environmental remediation charges. See Note 15: Legal Proceedings, Commitments and Contingencies for more information.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2018
INCOME TAXES	INCOME TAXES This note provides details about our income taxes applicable to continuing operations: • earnings before income taxes, • provision for income taxes, • effective income tax rate, • deferred tax assets and liabilities, • unrecognized tax benefits and • our ongoing IRS tax matter. Income taxes related to discontinued operations are discussed in Note 4: Discontinued Operations and Other Divestitures . The Income Taxes section of Note 1: Summary of Significant Accounting Policies provides details about how we account for our income taxes. Tax Legislation On December 22, 2017, H.R. 1, commonly known as the Tax Cuts and Jobs Act (the "Tax Act"), was enacted. The Tax Act contains significant changes to corporate taxation, including the reduction of the corporate tax rate from 35 percent to 21 percent . As a result of the reduction in the corporate tax rate, we revalued our deferred tax assets and liabilities and recorded a tax expense of $74 million during 2017, which reduced our net deferred tax asset. We were not required to pay a repatriation tax due to the fact that we had no foreign undistributed earnings at December 31, 2017. The most significant effects of the Tax Act provisions for 2018 include a reduction to our overall estimated annual effective tax rate primarily due to the reduced corporate tax rate, and new limitations on certain business deductions. During first quarter 2018, we adopted ASU 2018-02 which allowed for the reclassification of certain income tax effects related to the Tax Act between "Accumulated other comprehensive loss” and “Retained earnings”. Refer to Note 1: Summary of Significant Accounting Policies for further details on this ASU and the related effect on our financial statements. Pension Contribution Tax Adjustment At the end of 2017, we revalued our deferred tax assets (including pension) to the 2018 federal tax rate of 21 percent , as a result of the Tax Act, as discussed above. During third quarter 2018, we announced actions intended to reduce the liabilities of our U.S. qualified pension plan while maintaining the plan’s current funded status and made a decision to contribute $300 million to our U.S. qualified pension plan (refer to Note 10: Pension and Other Postretirement Benefit Plans ). We were able to deduct this contribution on our 2017 U.S. federal tax return at the 2017 federal tax rate of 35 percent . This resulted in an incremental $41 million tax benefit for the portion attributable to our TRSs during third quarter 2018. EARNINGS BEFORE INCOME TAXES Domestic and Foreign Earnings from Continuing Operations Before Income Taxes DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Domestic earnings $ 556 $ 643 $ 353 Foreign earnings 251 73 151 Total earnings before income taxes $ 807 $ 716 $ 504 PROVISION FOR INCOME TAXES Provision (Benefit) for Income Taxes from Continuing Operations DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Current: Federal $ (69 ) $ 10 $ 1 State (5 ) — 1 Foreign 61 82 11 Total current (13 ) 92 13 Deferred: Federal 45 61 37 State 12 (18 ) (3 ) Foreign 15 (1 ) 42 Total deferred 72 42 76 Total income tax provision (benefit) $ 59 $ 134 $ 89 EFFECTIVE INCOME TAX RATE Effective Income Tax Rate Applicable to Continuing Operations DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 U.S. federal statutory income tax $ 170 $ 250 $ 177 State income taxes, net of federal tax benefit 8 (2 ) (3 ) REIT income not subject to federal income tax (116 ) (198 ) (99 ) SDT settlement 21 — — Tax effect of U.S. corporate rate change — 74 — Voluntary pension contribution (41 ) — — Foreign taxes 15 54 (4 ) Repatriation of Canadian earnings — (22 ) 24 Other, net 2 (22 ) (6 ) Total income tax provision (benefit) $ 59 $ 134 $ 89 Effective income tax rate 7.3 % 18.8 % 17.6 % DEFERRED TAX ASSETS AND LIABILITIES Deferred tax assets and liabilities reflect the future tax effect created by differences between the timing of when income or deductions are recognized for pretax financial book reporting purposes versus income tax purposes. Deferred tax assets represent a future tax benefit (or reduction to income taxes in a future period), while deferred tax liabilities represent a future tax obligation (or increase to income taxes in a future period). Our deferred tax assets and liabilities have been revalued for the reduction in the U.S. corporate tax rate. Balance Sheet Classification of Deferred Income Tax Assets (Liabilities) Related to Continuing Operations DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Net noncurrent deferred tax asset $ 15 $ 268 Net noncurrent deferred tax liability (43 ) — Net deferred tax asset (liability) $ (28 ) $ 268 Items Included in Our Deferred Income Tax Assets (Liabilities) DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Deferred tax assets: Postretirement benefits $ 37 $ 50 Pension 75 306 State tax credits 51 56 Other reserves 13 38 Depletion 41 40 Excess interest 30 — Incentive compensation 20 23 Workers compensation 18 19 Net operating loss carryforwards 19 18 Other 83 70 Gross deferred tax assets 387 620 Valuation allowance (61 ) (63 ) Net deferred tax assets 326 557 Deferred tax liabilities: Property, plant and equipment (197 ) (154 ) Timber installment notes (116 ) (116 ) Other (41 ) (19 ) Net deferred tax liabilities (354 ) (289 ) Net deferred tax asset (liability) (28 ) 268 Other Information About Our Deferred Income Tax Assets (Liabilities) Other information about our deferred income tax assets (liabilities) include: • net operating loss and credit carryforwards, • valuation allowances and • reinvestment of undistributed earnings. Net Operating Loss and Credit Carryforwards Our gross federal, state and foreign net operating loss carryforwards as of the end of 2018 totaled $584 million as follows: • U.S. REIT - $223 million , which expire from 2031 through 2036 ; • State - $361 million , which expire from 2019 through 2037 ; and • Foreign - none currently recorded. Our gross state credit carryforwards at the end of 2018 totaled $65 million , which includes $14 million that expire from 2019 through 2032 and $51 million that do not expire. Our U.S. TRS has $6 million in foreign tax credit carryforwards that expire in 2027 . Valuation Allowances With the exception of the valuation allowance discussed below, we believe it is more likely than not that we will have sufficient future taxable income to realize our deferred tax assets. Our valuation allowance on our deferred tax assets was $61 million at the end of 2018 , related to state credits, state net operating losses and passive foreign tax credits. Reinvestment of Undistributed Earnings We have historically asserted it is our intent to reinvest the earnings of our foreign subsidiaries. In fourth quarter 2018 , we changed our position regarding the earnings of our Canadian subsidiary. Our change in assertion was based on the company’s review of global cash management and planned capital deployment, taking into consideration the effects of the Tax Act. As of 2018 , our assertion is to permanently reinvest approximately 10 percent of our Canadian earnings. We have no other foreign subsidiaries with undistributed earnings. Accordingly, deferred taxes have been provided primarily related to Canadian withholding taxes associated with Canadian earnings no longer considered permanently reinvested. UNRECOGNIZED TAX BENEFITS Unrecognized tax benefits represent potential future obligations to taxing authorities if uncertain tax positions we have taken on previously filed tax returns are not sustained. The total gross amount of unrecognized tax benefits as of December 31, 2018 , and 2017 , is $3 million and $4 million , of which a net amount of $1 million and $2 million , respectively, would affect our tax rate if recognized. The net liability recorded in our Consolidated Balance Sheet related to unrecognized tax benefits is $1 million as of December 31, 2018 , comprised of the $3 million gross unrecognized tax benefit amount net of $2 million in loss carryforwards available to offset the liability. The net liability as of December 31, 2017 , was $2 million , comprised of $4 million gross unrecognized tax benefit amount net of $2 million loss carryforwards available to offset the liability. In accordance with our accounting policy, we accrue interest and penalties related to unrecognized tax benefits as a component of income tax expense. See Note 1: Summary of Significant Accounting Policies. Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Balance at beginning of year $ 4 $ 6 Lapse of statute (1 ) (2 ) Balance at end of year $ 3 $ 4 As of December 31, 2018 , none of our U.S. federal income tax returns or foreign jurisdiction income tax returns are under examination. Our U.S. federal income tax returns are open to examination for years 2015 forward and foreign jurisdictions income tax returns are open to examination for years 2010 forward. We are undergoing examinations in state jurisdictions for tax years 2009 through 2017, with tax years 2009 forward open to examination. We do not expect that the outcome of any examination will have a material effect on our consolidated financial statements; however, audit outcomes and the timing of audit settlements are subject to significant uncertainty. In the next 12 months, we estimate a decrease of $1 million in unrecognized tax benefits due to the lapse of applicable statutes of limitation. RESOLUTION OF IRS MATTER In connection with the merger with Plum Creek, we acquired equity interests in Southern Diversified Timber, LLC, a timberland joint venture (Timberland Venture) with an affiliate of Campbell Global LLC (TCG Member). On August 31, 2016, the Timberland Venture redeemed TCG Member's interest and became a fully consolidated, wholly-owned subsidiary of Weyerhaeuser. We received a Notice of Final Partnership Administrative Adjustment (FPAA), dated July 20, 2016, from the Internal Revenue Service (IRS) in regard to Plum Creek's 2008 U.S. federal income tax treatment of the transaction forming the Timberland Venture. The IRS asserted that the transfer of the timberlands to the Timberland Venture was a taxable transaction to Plum Creek at the time of the transfer rather than a nontaxable capital contribution. We subsequently filed a petition in the U.S. Tax Court to contest this adjustment. On February 8, 2019, we entered into a closing agreement with the IRS to settle this dispute. Under the terms of the agreement, the company paid approximately $21 million of corporate tax. This amount was recorded as tax expense in fourth quarter 2018. No interest or penalties will be assessed. The parties have filed a stipulated decision with the U.S. Tax Court, pursuant to which the Court will officially close the matter.

GEOGRAPHIC AREAS

GEOGRAPHIC AREAS	12 Months Ended
	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
GEOGRAPHIC AREAS	GEOGRAPHIC AREAS This note provides selected key financial data according to the geographical locations of our customers. The selected key financial data includes: • sales to unaffiliated customers, • export sales from the U.S. and • long-lived assets. SALES Our sales to unaffiliated customers outside the U.S. are primarily to customers in Canada, Japan and China. Our export sales are comprised primarily of logs, lumber and wood chips to Japan and China. Sales by Geographic Area DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Sales to unaffiliated customers: U.S. $ 6,365 $ 6,168 $ 5,451 Canada 519 472 341 Japan 410 352 369 China 120 107 108 Other foreign countries 62 97 96 Total $ 7,476 $ 7,196 $ 6,365 Export sales from the U.S.: Japan $ 338 $ 295 $ 314 China 113 102 103 Other foreign countries 153 148 98 Total $ 604 $ 545 $ 515 LONG-LIVED ASSETS Our long-lived assets — used in the generation of revenues in the different geographical areas — are nearly all in the U.S. and Canada. Our long-lived assets include: • property and equipment, including construction in progress, • timber and timberlands, • minerals and mineral rights and • goodwill. Long-Lived Assets by Geographic Area DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, DECEMBER 31, U.S. $ 14,778 $ 14,922 $ 15,700 Canada 220 223 206 Other foreign countries — — 527 Total (1) $ 14,998 $ 15,145 $ 16,433 (1) Amounts for December 31, 2016, include assets from discontinued operations.

SELECTED QUARTERLY FINANCIAL IN

SELECTED QUARTERLY FINANCIAL INFORMATION (unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY FINANCIAL INFORMATION (unaudited)	SELECTED QUARTERLY FINANCIAL INFORMATION (unaudited) Quarterly financial data provides a review of our results and performance throughout the year. Our earnings per share for the full year do not always equal the sum of the four quarterly earnings-per share amounts because of common share activity during the year. As the company’s common shares are traded on the New York Stock Exchange (NYSE), market price information such as the high and low trading prices of our common shares can be found under the symbol WY. Key Quarterly Financial Data for the Last Two Years DOLLAR AMOUNTS IN MILLIONS EXCEPT PER-SHARE FIGURES FIRST QUARTER SECOND QUARTER THIRD QUARTER FOURTH QUARTER FULL YEAR 2018: Net sales $ 1,865 $ 2,065 $ 1,910 $ 1,636 $ 7,476 Operating income from continuing operations 404 476 337 177 1,394 Earnings (loss) from continuing operations before income taxes 299 382 240 (114 ) 807 Net earnings (loss) 269 317 255 (93 ) 748 Basic and diluted net earnings (loss) per share 0.35 0.42 0.34 (0.12 ) 0.99 Dividends paid per share 0.32 0.32 0.34 0.34 1.32 2017: Net sales $ 1,693 $ 1,808 $ 1,872 $ 1,823 $ 7,196 Operating income from continuing operations 293 157 205 476 1,131 Earnings (loss) from continuing operations before income taxes 181 58 103 374 716 Net earnings (loss) 157 24 130 271 582 Basic and diluted net earnings (loss) per share 0.21 0.03 0.17 0.36 0.77 Dividends paid per share 0.31 0.31 0.31 0.32 1.25

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
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.
Our Business Segments	Our Business Segments Reportable business segments are determined based on the company’s "management approach," as defined by Financial Accounting Standards Board (FASB) ASC 280, “Segment Reporting.” The management approach is based on the way the chief operating decision maker organizes the segments within a company for making decisions about resources to be allocated and assessing their performance. 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 leased recreational access Real Estate & ENR Sales of timberlands, rights to explore for and extract hard minerals, construction materials, oil and gas production, wind, solar and coal Wood Products Softwood lumber, engineered wood products, structural panels, medium density fiberboard and building materials distribution We also transfer raw materials, semi-finished 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.
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; • pension plan assets measured at fair value; 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:
Reclassifications	Reclassifications We have reclassified certain balances and results from prior years to be consistent with our 2018 reporting. This makes year-to-year comparisons easier. Our reclassifications had no effect on consolidated net earnings or equity.
New Accounting Pronouncements	New Accounting Pronouncements Lease Recognition In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, which requires lessees to recognize assets and liabilities for the rights and obligations created by those leases and requires 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 adopted this standard on January 1, 2019, using the modified retrospective transition approach at the beginning of the adoption period through a cumulative-effect adjustment to retained earnings. With this adoption approach, financial information will not be updated and disclosures required under the new standard will not be provided for dates and periods before January 1, 2019. In addition, the standard provides a number of optional practical expedients in transition. The adoption resulted in the recognition of additional right-of-use assets and lease liabilities for operating leases of less than 2 percent of our total assets on our Consolidated Balance Sheet . These leases are primarily related to vehicles, equipment, office and warehouse leases disclosed in Note 15: Legal Proceedings, Commitments and Contingencies . Reclassification of Certain Amounts from Accumulated Other Comprehensive Loss In February 2018, the FASB issued ASU 2018-02, which allows for the reclassification of certain income tax effects related to the Tax Cuts and Jobs Act (Tax Act) between “Accumulated other comprehensive loss” and “Retained earnings.” This ASU provides that adjustments to deferred tax liabilities and assets related to a change in tax laws be included in “Income from continuing operations”, even in situations where the related items were originally recognized in “Other comprehensive income (loss).” The amendments in this ASU are effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. Adoption of this ASU is to be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the tax laws was recognized. We adopted this ASU during first quarter 2018 using the period of adoption method, which resulted in a reclassification of $253 million from "Accumulated other comprehensive loss" to "Retained earnings" on our Consolidated Balance Sheet due to changes in federal statutory and effective state rates. In general, tax effects unrelated to the Tax Act are released from accumulated other comprehensive loss using the portfolio approach. In January 2016, the FASB issued ASU 2016-01, which updates certain aspects of recognition, measurement, presentation and disclosure of financial instruments. We adopted ASU 2016-01 in first quarter 2018, which resulted in a reclassification of accumulated unrealized gains on available-for-sale securities of $9 million from "Accumulated other comprehensive loss" to "Retained earnings" on our Consolidated Balance Sheet . Revenue Recognition In May 2014, the FASB issued 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. 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. In February 2017, FASB issued ASU 2017-05, which clarifies the scope of ASC 610-20 and affects accounting for partial sales of nonfinancial assets. We adopted this accounting standard update on 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 have adopted using the cumulative effect method. The adoption of the new revenue recognition guidance does not materially affect our Consolidated Statement of Operations , Consolidated Balance Sheet , or Consolidated Statement of Cash Flows .
Property and Equipment	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. • We capitalize costs associated with logging roads that we intend to utilize for a period longer than one year. These roads are then amortized over an estimated service life. • 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	Timber and Timberlands We carry timber and timberlands at cost less depletion. 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. 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. In addition, the duration of the harvest cycle varies by geographic region and species of timber. Depletion rate calculations do not include estimates for: • future silviculture or sustainable forest management costs associated with existing stands • future reforestation costs associated with a stand's final harvest; and • future volume in connection with the replanting of a stand subsequent to its final harvest 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 Costs of sales. 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	Impairment of Long-Lived Assets We review the carrying value of long-lived assets whenever an event or a change in circumstance ("a triggering event") indicates that the carrying value of the asset or asset group may not be recoverable through future operations. The carrying value is the original cost, less accumulated depreciation and any past impairments recorded. 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.
Financial Instruments	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 market approach, which is based on quoted market prices we received for the same types and issues of our debt. We believe that our variable rate long-term debt and line of credit 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 may have negative book cash balances due to outstanding checks that have not yet been paid by the bank. These negative balances would be included in "Accounts payable" on our Consolidated Balance Sheet . Changes in these negative cash balances would be reported as financing activities in our Consolidated Statement of Cash Flows . We had no negative book cash balances as of December 31, 2018 , and December 31, 2017 .
Concentration of Risk	Concentration of Risk We disclose customers that represent a concentration of risk. As of December 31, 2018 , and December 31, 2017 , no customer accounted for 10 percent or more of our net sales
Revenue Recognition	Revenue Recognition PERFORMANCE OBLIGATIONS A performance obligation, as defined in ASC Topic 606, is a promise in a contract to transfer a distinct good or service to a customer. A contract's transaction price is allocated to each distinct performance obligation and recognized as revenue at the point in time, or over the period, in which the performance obligation is satisfied. Performance obligations associated with delivered log sales are typically satisfied when the logs are delivered to our customers’ mills or delivered to an ocean vessel in the case of export sales. Performance obligations associated with the sale of wood products are typically satisfied when the products are shipped. The company has elected, as an accounting policy, to treat shipping and handling that is performed after a customer obtains control of the product as an activity required to fulfill the promise to transfer the good; therefore we will not evaluate this requirement as a separate performance obligation. Customers are generally invoiced shortly after logs are delivered or after wood products are shipped, with payment generally due within a month or less of the invoice date. ASC Topic 606 requires entities to consider significant financing components of contracts with customers, though allows for the use of a practical expedient when the period between satisfaction of a performance obligation and payment receipt is one year or less. Given the nature of our revenue transactions, we have elected to utilize this practical expedient. Performance obligations associated with real estate sales are generally met when placed into escrow and all conditions of closing have been satisfied. CONTRACT ESTIMATES Substantially all of the company’s performance obligations are satisfied as of a point in time. Therefore, there is little judgment in determining when control transfers for our business segments as described above. The transaction price for log sales generally equals the amount billed to our customer for logs delivered during the accounting period. For the limited number of log sales subject to a long-term supply agreement, the transaction price is variable but is known at the time of billing. For wood products sales, the transaction price is generally the amount billed to the customer for the products shipped but may be reduced slightly for estimated cash discounts and rebates. There are no significant contract estimates related to the real estate business. CONTRACT BALANCES In general, customers are billed and a receivable is recorded as we ship and/or deliver wood products and logs. We generally receive payment shortly after products have been received by our customers. Contract asset and liability balances are immaterial. For real estate sales, the company receives the entire consideration in cash at closing.
Inventories	Inventories We state inventories at the lower of cost or net realizable value. 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	Shipping and Handling Costs We classify shipping and handling costs in "Costs of sales" on our Consolidated Statement of Operations .
Income Taxes	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 reporting 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.
Pension and Other Postretirement Benefit Plans	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 defined benefit pension plans covering approximately half of our employees. Determination of benefits differs for salaried, hourly and union employees, as follows: • 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 10: Pension and Other Postretirement Benefit Plans provides additional information about changes made in our postretirement benefit plans during 2018 and 2017 . Valuation of Our Plan Assets Pension assets are stated at fair value as of the reporting date. Fair value is based on the amount that would be received to sell an asset or paid to settle a liability in an orderly transaction between market participants at the reporting date. We do not consider forced or distressed sale scenarios. 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 for 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 is: • Level 1: Inputs are unadjusted quoted prices for identical assets or 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. Investments for which fair value is measured using the net asset value per share as a practical expedient are not categorized within the fair value hierarchy. Cash and short-term investments are valued at cost, which approximates market. Fixed income investments are valued at exit prices quoted in active or non-active markets or based on observable inputs. Hedge funds, private equities, and related fund units are valued based on the net asset values of the funds. These values represent the per-unit price at which new investors are permitted to invest and existing investors are permitted to exit. When net asset values as of the end of the year have not been received, we estimate fair value by adjusting the most recently reported net asset values for market events and cash flows between the interim date and the end of the year. Derivative instruments are valued based upon valuation statements received from each derivative’s counterparty. Some of these contracts are not publicly traded.
Environmental Remediation	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 $126 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.
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 and • performance share units 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 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.
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.

BUSINESS SEGMENTS (Tables)

BUSINESS SEGMENTS (Tables)	12 Months Ended
	Dec. 31, 2018
Sales and Contribution (Charge) to Earnings	Sales and Contribution (Charge) to Earnings DOLLAR AMOUNTS IN MILLIONS TIMBERLANDS REAL ESTATE WOOD UNALLOCATED ITEMS (1) AND INTERSEGMENT ELIMINATIONS CONSOLIDATED Sales to unaffiliated customers 2018 $ 1,915 $ 306 $ 5,255 $ — $ 7,476 2017 $ 1,942 $ 280 $ 4,974 $ — $ 7,196 2016 $ 1,805 $ 226 $ 4,334 $ — $ 6,365 Intersegment sales 2018 $ 802 $ 1 $ — $ (803 ) $ — 2017 $ 762 $ 1 $ — $ (763 ) $ — 2016 $ 840 $ 1 $ 68 $ (909 ) $ — Contribution (charge) to earnings from continuing operations 2018 $ 583 $ 127 $ 838 $ (366 ) $ 1,182 2017 $ 532 $ 146 $ 569 $ (138 ) $ 1,109 2016 $ 499 $ 55 $ 512 $ (131 ) $ 935 (1) Unallocated items are gains or charges not related to or allocated to an individual operating segment. They include a portion of items such as share-based compensation expense, pension and postretirement costs, foreign exchange transaction gains and losses, interest income and other, and the elimination of intersegment profit in inventory and LIFO.
Reconciliation of Contribution to Earnings to Net Earnings	Reconciliation of Contribution to Earnings to Net Earnings DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Net contribution to earnings from continuing operations $ 1,182 $ 1,109 $ 935 Net contribution to earnings from discontinued operations — — 957 Total contribution to earnings 1,182 1,109 1,892 Interest expense, net of capitalized interest (1) (375 ) (393 ) (436 ) Income before income taxes (1) 807 716 1,456 Income taxes (1) (59 ) (134 ) (429 ) Net earnings $ 748 $ 582 $ 1,027 (1) Results shown for 2016 include amounts for both continuing and discontinued operations. Refer to Note 4: Discontinued Operations and Other Divestitures for further information.
Additional Financial Information	Additional Financial Information DOLLAR AMOUNTS IN MILLIONS TIMBERLANDS REAL ESTATE & ENR WOOD PRODUCTS UNALLOCATED ITEMS CONSOLIDATED Depreciation, depletion and amortization 2018 $ 319 $ 14 $ 149 $ 4 $ 486 2017 $ 356 $ 15 $ 145 $ 5 $ 521 2016 $ 366 $ 13 $ 129 $ 4 $ 512 Charges for integration and restructuring, closures and asset impairments (1) 2018 $ — $ — $ 2 $ — $ 2 2017 $ 147 $ — $ 13 $ 34 $ 194 2016 $ — $ 15 $ 7 $ 148 $ 170 Capital expenditures 2018 $ 117 $ — $ 306 $ 4 $ 427 2017 $ 115 $ 2 $ 299 $ 3 $ 419 2016 $ 116 $ 1 $ 297 $ 11 $ 425 (1) See Note 18: Charges for Integration and Restructuring, Closures and Asset Impairments for more information.
Total Assets	Total Assets DOLLAR AMOUNTS IN MILLIONS TIMBERLANDS and REAL ESTATE & ENR (1) WOOD PRODUCTS UNALLOCATED ITEMS CONSOLIDATED Total assets 2018 $ 13,838 $ 2,234 $ 1,177 $ 17,249 2017 $ 14,122 $ 2,145 $ 1,792 $ 18,059 (1) Assets attributable to the Real Estate & ENR business segment are combined with total assets for the Timberlands segment as we do not produce separate balance sheets internally.

REVENUE RECOGNITION (Tables)

REVENUE RECOGNITION (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from External Customer
Revenue by Major Products	MAJOR PRODUCTS A Reconciliation of Revenue Recognized by our Major Products: DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Net Sales to Unaffiliated Customers: Timberlands Segment Delivered logs (1) : West Domestic sales 503 473 410 Export sales 484 442 455 Subtotal West 987 915 865 South 625 616 566 North 99 95 91 Other 41 59 38 Subtotal delivered logs sales 1,752 1,685 1,560 Stumpage and pay-as-cut timber 59 73 85 Recreational and other lease revenue 59 59 44 Other (2) 45 125 116 Net Sales attributable to Timberlands Segment 1,915 1,942 1,805 Real Estate & ENR Segment Real estate 229 208 172 Energy and natural resources 77 72 54 Net sales attributable to Real Estate & ENR Segment 306 280 226 Wood Products Segment Structural lumber 2,258 2,058 1,839 Oriented strand board 891 904 707 Engineered solid section 521 500 450 Engineered I-joists 336 336 290 Softwood plywood 200 176 174 Medium density fiberboard 177 183 158 Complementary building products 584 541 515 Other (3) 288 276 201 Net sales attributable to Wood Products Segment 5,255 4,974 4,334 Total $ 7,476 $ 7,196 $ 6,365 (1) The West region includes Washington and Oregon. The South region includes Virginia, North Carolina, South Carolina, Florida, Georgia, Alabama, Mississippi, Louisiana, Arkansas, Texas and Oklahoma. The North region includes West Virginia, Maine, New Hampshire, Vermont, Michigan, Wisconsin and Montana. Other includes our Canadian operations and former Twin Creeks Venture (terminated in December 2017). (2) Other Timberlands sales include sales of seeds and seedlings, chips, as well as sales from our former Uruguayan operations (sold during third quarter 2017). Our former Uruguayan operations included logs, plywood and hardwood lumber harvested or produced. Refer to Note 4: Discontinued Operations and Other Divestitures for further information. (3) Includes chips and other byproducts.

DISCONTINUED OPERATIONS AND O_2

DISCONTINUED OPERATIONS AND OTHER DIVESTITURES (Tables)	12 Months Ended
	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales and Net Earnings from Discontinued Operations	Sales and Net Earnings from Discontinued Operations DOLLAR AMOUNTS IN MILLIONS 2016 (1) Total net sales $ 1,537 Costs of sales 1,283 Gross margin 254 Selling expenses 12 General and administrative expenses 29 Research and development expenses 5 Charges for integration and restructuring, closures and asset impairments (2) 63 Other operating income, net (27 ) Operating income 172 Equity loss from joint venture (4 ) Interest expense, net of capitalized interest (5 ) Earnings from discontinued operations before income taxes 163 Income taxes (97 ) Net earnings from operations 66 Net gain on divestiture of Cellulose Fibers 546 Net earnings from discontinued operations $ 612 (1) Discontinued operations in 2016 includes 335 days of the pulp business, 305 days of our printing papers joint venture operations, and 244 days of the liquid packaging board business. (2) Charges for integration and restructuring, closures and asset impairments consist of costs related to our strategic evaluation of the Cellulose Fibers businesses and transaction-related costs.
Cash Flows from Discontinued Operations	Cash Flows from Discontinued Operations DOLLAR AMOUNTS IN MILLIONS 2016 (1) Net cash provided by operating activities $ 196 Net cash provided by investing activities $ 2,356 (1) Discontinued operations in 2016 includes 335 days of the pulp business, 305 days of our printing papers joint venture operations, and 244 days of the liquid packaging board business, and the cash flows associated with the CF divestitures.
Cellulose Fibers
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Components of the net gain on divestitures	The following table presents the components of the net gain on the divestiture of Cellulose Fibers: DOLLAR AMOUNTS IN MILLIONS 2016 Proceeds, net of cash and cash equivalents disposed of $ 2,486 Less: Net book value of assets and liabilities disposed of (1,678 ) Transaction costs, net of reimbursement (19 ) (1,697 ) Pretax gain on Cellulose Fibers divestitures 789 Income taxes (243 ) Net gain on Cellulose Fibers divestitures $ 546

MERGER WITH PLUM CREEK (Tables)

MERGER WITH PLUM CREEK (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Summarized Unaudited Pro Forma Information that Presents Combined Amounts as if this Merger Occurred at the Beginning of 2015 [Table Text Block]	Summarized Unaudited Pro Forma Information that Presents Combined Amounts as if this Merger Occurred at the Beginning of 2015 DOLLAR AMOUNTS IN MILLIONS, EXCEPT PER-SHARE FIGURES 2016 Net sales $ 6,525 Net earnings from continuing operations attributable to Weyerhaeuser common shareholders $ 519 Net earnings from continuing operations per share attributable to Weyerhaeuser common shareholders, basic $ 0.69 Net earnings from continuing operations per share attributable to Weyerhaeuser common shareholders, diluted $ 0.68

NET EARNINGS PER SHARE (Tables)

NET EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2018
Schedule of Basic and Diluted Earnings per Share	Calculation of Weighted Average Number of Outstanding Common Shares - Dilutive SHARES IN THOUSANDS 2018 2017 2016 Weighted average number of outstanding shares - basic 754,556 753,085 718,560 Dilutive potential common shares: Stock options 1,310 2,571 2,672 Restricted stock units 566 582 756 Performance share units 395 428 413 Total effect of outstanding dilutive potential common shares 2,271 3,581 3,841 Weighted average number of outstanding common shares - dilutive 756,827 756,666 722,401
Potential Shares Not Included in the Computation of Diluted Earnings per Share	Potential Shares Not Included in the Computation of Diluted Earnings per Share SHARES IN THOUSANDS 2018 2017 2016 Stock options 2,402 1,351 1,462 Performance share units 1,080 799 384

INVENTORIES (Tables)

INVENTORIES (Tables)	12 Months Ended
	Dec. 31, 2018
Inventories as of the End of Our Last Two Years	Inventories as of the End of Our Last Two Years DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, LIFO inventories: Logs $ 11 $ 17 Lumber, plywood, panels, and fiberboard 75 66 Other products 10 10 FIFO or moving average cost inventories: Logs 35 38 Lumber, plywood, panels, fiberboard and engineered wood products 86 91 Other products 83 77 Materials and supplies 89 84 Total $ 389 $ 383

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2018
Property and Equipment [Line Items]
Carrying Value of Property and Equipment and Estimated Service Lives	Carrying Value of Property and Equipment and Estimated Service Lives DOLLAR AMOUNTS IN MILLIONS RANGE OF LIVES DECEMBER 31, DECEMBER 31, Property and equipment, at cost: Land N/A $ 87 $ 88 Buildings and improvements 15-40 942 867 Machinery and equipment 5-25 3,240 3,037 Roads 10-35 785 782 Other 3-10 179 182 Total cost 5,233 4,956 Accumulated depreciation and amortization (3,376 ) (3,338 ) Property and equipment, net $ 1,857 $ 1,618

RELATED PARTIES (Tables)

RELATED PARTIES (Tables)	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Schedule of Changes in our Deposit from Contribution of Timberlands	Changes in our deposit from contribution of timberlands to related party balance during 2017 were as follows: DOLLAR AMOUNTS IN MILLIONS Balance at December 31, 2016 $ 426 Lease payments to Twin Creeks Venture (8 ) Distributions from Twin Creeks Venture 2 Recognition of contributed timberlands (420 ) Balance at December 31, 2017 $ —

PENSION AND OTHER POSTRETIREM_2

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Tables)	12 Months Ended
	Dec. 31, 2018
Funded Status of Our Plans	The funded status of the plans we sponsor is determined by comparing the projected benefit obligation with the fair value of plan assets at the end of the year. The following table demonstrates how our plans' funded status is reflected on the Consolidated Balance Sheet . DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS 2018 2017 2018 2017 Funded status: Fair value of plan assets $ 4,930 $ 5,514 $ 18 $ — Projected benefit obligations (5,263 ) (6,795 ) (166 ) (200 ) Funded status $ (333 ) $ (1,281 ) $ (148 ) $ (200 ) Presentation on our Consolidated Balance Sheet: Noncurrent assets $ 74 $ 45 $ — $ — Current liabilities (18 ) (21 ) (10 ) (19 ) Noncurrent liabilities (389 ) (1,305 ) (138 ) (181 ) Funded status $ (333 ) $ (1,281 ) $ (148 ) $ (200 )
Changes in Fair Value of Plan Assets	Changes in Fair Value of Plan Assets DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS 2018 2017 2018 2017 Fair value of plan assets at beginning of year (estimated) $ 5,514 $ 5,351 $ — $ — Adjustment for final fair value of plan assets 44 18 — — Actual return on plan assets 123 553 — — Foreign currency translation (73 ) 59 — — Employer contributions and benefit payments 345 57 36 20 Plan participants’ contributions — — 4 6 Plan transfers 1 3 — — Benefits paid (includes lump sum settlements) (1,024 ) (527 ) (22 ) (26 ) Fair value of plan assets at end of year (estimated) $ 4,930 $ 5,514 $ 18 $ —
Changes in Projected Benefit Obligations of Our Pension and Other Postretirement Benefit Plans	Changes in Projected Benefit Obligations of Our Pension and Other Postretirement Benefit Plans DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS 2018 2017 2018 2017 Reconciliation of projected benefit obligation: Projected benefit obligation beginning of year $ 6,795 $ 6,469 $ 200 $ 225 Service cost 37 35 — — Interest cost 236 264 7 8 Plan participants’ contributions — — 4 6 Actuarial (gains) losses (718 ) 489 (18 ) (18 ) Foreign currency translation (69 ) 59 (5 ) 5 Benefits paid (includes lump sum settlements) (1,024 ) (527 ) (22 ) (26 ) Plan amendments and other 5 3 — — Plan transfers 1 3 — — Projected benefit obligation at end of year $ 5,263 $ 6,795 $ 166 $ 200
Schedules of Allocation of Our Plans' Assets	The net pension plan assets, when categorized in accordance with this fair value hierarchy, are as follows. Investments valued using net asset value (NAV) as a practical expedient are presented to reconcile with total plan assets. DOLLAR AMOUNTS IN MILLIONS 2018 LEVEL 1 LEVEL 2 LEVEL 3 NAV TOTAL Pension trust investments: Cash and short-term investments $ 275 $ 12 $ — $ — $ 287 Common and preferred stock — — — — — Fixed income investments: Corporate — 1,054 — — 1,054 Government — 426 — — 426 Hedge fund and related investments — — 3 1,811 1,814 Private equity and related investments — — 65 1,014 1,079 Derivative instruments — 15 262 — 277 Total pension trust investments 275 1,507 330 2,825 4,937 Accrued liabilities, net (17 ) Pension trust net assets 4,920 Canadian nonregistered plan assets: Cash and short-term investments 5 — — — 5 Common and preferred stock 5 — — — 5 Total Canadian nonregistered plan assets 10 — — — 10 Total plan assets $ 4,930 DOLLAR AMOUNTS IN MILLIONS 2017 LEVEL 1 LEVEL 2 LEVEL 3 NAV TOTAL Pension trust investments: Cash and short-term investments $ 580 $ 2 $ — $ — $ 582 Common and preferred stock 1 — — — 1 Hedge fund and related investments 59 — 10 3,168 3,237 Private equity and related investments — — 102 1,120 1,222 Derivative instruments — 31 445 — 476 Total pension trust investments 640 33 557 4,288 5,518 Accrued liabilities, net (16 ) Pension trust net investments 5,502 Canadian nonregistered plan assets: Cash and short-term investments 6 — — — 6 Common and preferred stock 6 — — — 6 Total Canadian nonregistered plan assets 12 — — — 12 Total plan assets $ 5,514
Reconciliation of Pension Plan Assets Measured at Level 3 Fair Value	A reconciliation of the beginning and ending balances of the pension plan assets measured at fair value using significant unobservable inputs (Level 3) is presented below: DOLLAR AMOUNTS IN MILLIONS INVESTMENTS Hedge funds and related investments Private equity and related investments Derivative instruments, net Total Balance as of December 31, 2016 $ 4 $ 75 $ 376 $ 455 Net realized gains (losses) (1 ) (30 ) 15 (16 ) Net change in unrealized gains (losses) 2 41 67 110 Purchases — 14 — 14 Sales (1 ) — — (1 ) Settlements — — (13 ) (13 ) Transfers into Level 3 6 19 — 25 Transfers out of Level 3 — (17 ) — (17 ) Balance as of December 31, 2017 10 102 445 557 Net realized gains (losses) — — 238 238 Net change in unrealized gains (losses) 1 (5 ) (184 ) (188 ) Purchases — 5 — 5 Sales — (2 ) — (2 ) Settlements — — (237 ) (237 ) Transfers into Level 3 — 18 — 18 Transfers out of Level 3 (8 ) (53 ) — (61 ) Balance as of December 31, 2018 $ 3 $ 65 $ 262 $ 330
Assumptions We Use in Estimating Health Care Benefit Costs	Assumptions We Use in Estimating Health Care Benefit Cost Trends 2018 2017 U.S. CANADA U.S. CANADA Weighted health care cost trend rate assumed for next year 7.80% for Pre-Medicare and 4.50% for HRA 4.90 % 8.40% for Pre-Medicare and 4.50% for HRA 5.10 % Rate that the cost trend rate gradually declines to 4.50 % 4.00 % 4.50 % 4.30 % Year the cost trend rate is reached 2037 2039 2037 2028
Effect of a One Percent Change in Health Care Costs	Effect of a One Percent Change in Health Care Costs AS OF DECEMBER 31, 2018 (DOLLAR AMOUNTS IN MILLIONS) 1% INCREASE 1% DECREASE Effect on total service and interest cost components Less than $1 Less than $(1) Effect on accumulated postretirement benefit obligation $ 5 $ (4 )
Net Periodic Benefit Cost (Credit)	Net Periodic Benefit Cost (Credit) DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS 2018 2017 2016 2018 2017 2016 Net periodic benefit cost (credit): Service cost (1) $ 37 $ 35 $ 48 $ — $ — $ — Interest cost 236 264 277 7 8 8 Expected return on plan assets (399 ) (409 ) (495 ) — — — Amortization of actuarial loss 225 195 156 8 8 9 Amortization of prior service cost (credit) 3 4 4 (8 ) (8 ) (7 ) Accelerated pension costs for Plum Creek merger-related change-in-control provisions — — 5 — — — Settlement charge 200 — — — — — Net periodic benefit cost (credit) $ 302 $ 89 $ (5 ) $ 7 $ 8 $ 10 (1) Service cost includes $13 million in 2016 for employees that were part of our Cellulose Fibers divestitures. These charges are included in our results of discontinued operations. Curtailment and special termination benefits are related to involuntary terminations due to restructuring activities.
Estimated Amortization from Cumulative Other Comprehensive Loss	Estimated Amortization from Accumulated Other Comprehensive Loss in 2019 DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS TOTAL Net actuarial loss $ 108 $ 7 $ 115 Prior service cost (credit) 4 (1 ) 3 Net effect cost $ 112 $ 6 $ 118
Estimated Projected Benefit Payments for the Next 10 Years	Estimated Projected Benefit Payments for the Next 10 Years DOLLAR AMOUNTS IN MILLIONS PENSION (1) OTHER POSTRETIREMENT BENEFITS 2019 $ 272 $ 17 2020 233 16 2021 231 15 2022 232 14 2023 234 14 2024-2028 1,161 57 (1) Estimated payments exclude future payments transferred in conjunction with our January 2019 group annuity contract purchase.
Qualified and Registered Plans [Member]
Schedules of Allocation of Our Plans' Assets	Assets within our qualified and registered pension plans in our U.S. and Canadian pension trusts were invested as follows: DECEMBER 31, 2018 DECEMBER 31, 2017 Cash and short-term investments 5.8 % 10.6 % Fixed income investments: Corporate 21.5 — Government 8.6 — Hedge funds and related investments 36.9 58.8 Private equity and related investments 21.9 22.2 Derivative instruments, net 5.6 8.7 Accrued liabilities (0.3 ) (0.3 ) Total 100.0 % 100.0 %
Pension
Rates We Use in Estimating Our Benefit Obligations	Rates We Use in Estimating Our Benefit Obligations PENSION DECEMBER 31, DECEMBER 31, Discount rates: United States 4.40 % 3.70 % Canada 3.70 % 3.50 % Lump sum distributions (1)(2) PPA Table PPA Table Rate of compensation increase: Salaried: United States 13.00% to 2.00% decreasing with participant age 13.00% to 2.00% decreasing with participant age Canada 3.25 % 3.25 % Hourly: United States 13.00% to 2.30% decreasing with participant age 13.00% to 2.30% decreasing with participant age Canada 3.00 % 3.00 % Lump sum or installment distributions election (2) 60.00 % 60.00 % (1) PPA Phased Table: Interest and mortality assumptions as mandated by Pension Protection Act of 2006 including the phase out of the prior interest rate basis in 2013. (2) U.S. qualified salaried and nonqualified plans only.
Estimating Our Net Periodic Benefit Costs	Estimating Our Net Periodic Benefit Costs PENSION 2018 2017 2016 Discount rates: United States 3.70 % 4.30 % 4.50 % Canada 3.50 % 3.70 % 4.00 % Lump sum distributions (1)(2) PPA Table PPA Table PPA Table Expected return on plan assets: Qualified/registered plans (3) 8.00 % 8.00 % 9.00% for all plans except 7.00% for plans assumed from Plum Creek Nonregistered plans 3.50 % 3.50 % 3.50 % Rate of compensation increase: Salaried: United States 13.00% to 2.00% decreasing with participant age 13.00% to 2.00% decreasing with participant age 13.00% to 2.00% decreasing with participant age Canada 3.25 % 3.50 % 3.50 % Hourly: United States 13.00% to 2.30% decreasing with participant age 13.00% to 2.30% decreasing with participant age 13.00% to 2.30% decreasing with participant age Canada 3.00 % 3.25 % 3.25 % Lump sum distributions election (2) 60.00 % 60.00 % 60.00 % (1) PPA Phased Table: Interest and mortality assumptions as mandated by Pension Protection Act of 2006 including the phase out of the prior interest rate basis in 2013. (2) U.S. qualified salaried and nonqualified plans only. (3) Beginning in 2017 we used an assumed expected return on plan assets of 8.00 percent for qualified and registered pension plans.
Derivative instruments | Qualified and Registered Plans [Member]
Schedules of Allocation of Our Plans' Assets	The table below shows the fair value and aggregate notional amount of the derivative instruments held by our pension trusts at the end of the last two years. DOLLAR AMOUNTS IN MILLIONS FAIR VALUE NOTIONAL DECEMBER 31, DECEMBER 31, DECEMBER 31, DECEMBER 31, Equity and fixed income index derivatives, net $ — $ 19 $ — $ 501 Foreign currency derivatives, net — 12 13 1,413 Futures contracts, net 15 — 1,073 — Total return swaps, net 262 445 558 1,443 Total $ 277 $ 476 $ 1,644 $ 3,357

ACCRUED LIABILITIES (Tables)

ACCRUED LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2018
Accrued Liabilities	Accrued liabilities were comprised of the following: DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Accrued compensation and employee benefit costs $ 192 $ 223 Accrued taxes payable 30 43 Customer rebates, volume discounts and deferred income 99 96 Interest 109 111 Product remediation accrual (Note 19) 2 98 Other 58 74 Total $ 490 $ 645

LINES OF CREDIT (Tables)

LINES OF CREDIT (Tables)	12 Months Ended
	Dec. 31, 2018
Other Letters of Credit and Surety Bonds	OTHER LETTERS OF CREDIT AND SURETY BONDS The amounts of other letters of credit and surety bonds we have entered into as of the end of our last two years are included in the following table: DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Letters of credit $ 38 $ 37 Surety bonds $ 123 $ 134

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Instrument [Line Items]
Long-Term Debt by Types and Interest Rates (Includes Current Portion)	Long-Term Debt by Types and Interest Rates (Includes Current Portion) DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, 7.00% debentures due 2018 — 62 7.375% notes due 2019 500 500 9.00% debentures due 2021 150 150 4.70% debentures due 2021 588 597 7.125% debentures due 2023 191 191 5.207% debentures due 2023 881 885 4.625% notes due 2023 500 500 3.25% debentures due 2023 324 324 8.50% debentures due 2025 300 300 7.95% debentures due 2025 136 136 7.70% debentures due 2026 150 150 7.35% debentures due 2026 62 62 7.85% debentures due 2026 100 100 Variable rate term loan credit facility matures 2026 225 225 6.95% debentures due 2027 300 300 7.375% debentures due 2032 1,250 1,250 6.875% debentures due 2033 275 275 Other 1 1 5,933 6,008 Less unamortized discounts (5 ) (5 ) Less unamortized debt expense (9 ) (11 ) Total $ 5,919 $ 5,992 Portion due within one year $ 500 $ 62
Amounts of Long-Term Debt Due Annually for the Next Five Years and the Total Amount Due After 2023	Amounts of Long-Term Debt Due Annually for the Next Five Years and the Total Amount Due After 2023 DOLLAR AMOUNTS IN MILLIONS (1) 2019 $ 500 2020 — 2021 719 2022 — 2023 1,876 Thereafter 2,798 (1) Excludes $26 million of unamortized discounts, capitalized debt expense and fair value adjustments (related to Plum Creek merger).

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2018
Estimated fair values and carrying values of our long-term debt and line of credit	The estimated fair values and carrying values of our long-term debt and line of credit consisted of the following: DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, 2018 DECEMBER 31, 2017 CARRYING VALUE FAIR VALUE (LEVEL 2) CARRYING VALUE FAIR VALUE (LEVEL 2) Long-term debt (including current maturities) and line of credit: Fixed rate $ 5,694 $ 6,345 $ 5,768 $ 6,823 Variable rate 650 650 224 225 Total Debt $ 6,344 $ 6,995 $ 5,992 $ 7,048

LEGAL PROCEEDINGS, COMMITMENT_2

LEGAL PROCEEDINGS, COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2018
Loss Contingencies [Line Items]
Changes in the Reserve for Environmental Remediation	Changes in the Reserve for Environmental Remediation DOLLAR AMOUNTS IN MILLIONS Reserve balance as of December 31, 2017 $ 48 Reserve charges and adjustments, net 27 Payments (13 ) Reserve balance as of December 31, 2018 $ 62
Changes in the Reserve for Asset Retirement Obligations	Changes in the Reserve for Asset Retirement Obligations DOLLAR AMOUNTS IN MILLIONS Reserve balance as of December 31, 2017 $ 32 Reserve charges and adjustments, net 11 Payments (12 ) Other adjustments (1) (2 ) Reserve balance as of December 31, 2018 $ 29 (1) Primarily related to a foreign currency remeasurement gain for our Canadian reforestation obligation.
Future Commitments on Operating Leases	Our operating lease commitments as of December 31, 2018 were: DOLLAR AMOUNTS IN MILLIONS 2019 $ 35 2020 29 2021 26 2022 24 2023 18 Thereafter 78

SHAREHOLDERS' INTEREST (Tables)

SHAREHOLDERS' INTEREST (Tables)	12 Months Ended
	Dec. 31, 2018
Reconciliation of Our Common Share Activity	Reconciliation of Our Common Share Activity SHARES IN THOUSANDS 2018 2017 2016 Outstanding at beginning of year 755,223 748,528 510,483 Issuance from merger with Plum Creek (Note 5) — — 278,887 Stock options exercised 2,026 5,970 2,571 Issued for restricted stock units 466 605 840 Issued for performance shares 86 120 219 Preference shares converted to common — — 23,345 Repurchased (11,410 ) — (67,817 ) Outstanding at end of year 746,391 755,223 748,528
Changes in amounts included in our accumulated other comprehensive loss by component	Changes in amounts included in our accumulated other comprehensive loss by component are: DOLLAR AMOUNTS IN MILLIONS PENSION OTHER POSTRETIREMENT BENEFITS Foreign currency translation adjustments Actuarial loss Prior service cost Actuarial loss Prior service credit Unrealized gains on available-for-sale securities Total Ending balance as of December 31, 2016 $ 232 $ (1,651 ) $ (9 ) $ (67 ) $ 29 $ 7 $ (1,459 ) Other comprehensive income (loss) before reclassifications (1) 32 (280 ) (2 ) 14 — 2 (234 ) Amounts reclassified from accumulated other comprehensive income (loss) to earnings (1)(2) — 129 3 5 (6 ) — 131 Total other comprehensive income (loss) 32 (151 ) 1 19 (6 ) 2 (103 ) Ending balance as of December 31, 2017 264 (1,802 ) (8 ) (48 ) 23 9 (1,562 ) Other comprehensive income (loss) before reclassifications (1) (54 ) 393 (5 ) 12 1 — 347 Amounts reclassified from accumulated other comprehensive income (loss) to earnings (1)(2)(3) — 322 3 6 (6 ) — 325 Total other comprehensive income (loss) (54 ) 715 (2 ) 18 (5 ) — 672 Reclassification of certain tax effects due to tax law changes (4) — (245 ) (1 ) (12 ) 5 — (253 ) Reclassification of accumulated unrealized gains on available-for-sale securities (5) — — — — — (9 ) (9 ) Net amounts reclassified from accumulated other comprehensive loss to retained earnings — (245 ) (1 ) (12 ) 5 (9 ) (262 ) Ending balance as of December 31, 2018 210 (1,332 ) (11 ) (42 ) 23 — (1,152 ) (1) Amounts are presented net of tax. (2) Amounts of actuarial loss and prior service (cost) credit are components of net periodic benefit cost (credit). See Note: 10: Pension and Other Postretirement Benefit Plans . (3) Amounts include a settlement charge totaling $200 million related to our U.S. qualified pension plan for the year ended December 31, 2018. See Note: 10: Pension and Other Postretirement Benefit Plan s for further detail. (4) We reclassified certain tax effects from tax law changes of $253 million from "Accumulated other comprehensive loss" to "Retained earnings" on our Consolidated Balance Sheet in accordance with ASU 2018-02. See Note 1: Summary of Significant Accounting Policies . (5) We reclassified accumulated unrealized gains from available-for-sale securities of $9 million from "Accumulated other comprehensive loss" to "Retained earnings" on our Consolidated Balance Sheet in accordance with ASU 2016-01. See Note 1: Summary of Significant Accounting Policies .

SHARE-BASED COMPENSATION (Table

SHARE-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2018
Schedule of Restricted Stock Units Activity	Activity The following table shows our RSU activity for 2018 . RESTRICTED STOCK UNITS (IN THOUSANDS) WEIGHTED AVERAGE GRANT-DATE FAIR VALUE Nonvested at December 31, 2017 1,515 $ 29.12 Granted 710 34.19 Vested (560 ) 28.81 Forfeited (72 ) $ 30.19 Nonvested at December 31, 2018 (1) 1,593 $ 31.41 (1) As of December 31, 2018, there were approximately 336 thousand RSUs that had met the requisite service period and will be released as identified in the grant terms.
Weighted Average Assumptions Used in Estimating the Value of Performance Share Units	Weighted Average Assumptions Used in Estimating the Value of Performance Share Units 2018 2017 2016 Performance period 1/1/2018-12/31/2020 1/1/2017 – 12/31/2019 1/1/2016 – 12/31/2018 Expected dividends 3.81% 3.74% 3.92% - 5.37% Risk-free rate 1.75% - 2.34% 0.68% - 1.55% 0.45% - 0.97% Volatility 17.30% - 21.52% 22.71% - 24.07% 21.87% - 28.09% Weighted average grant-date fair value $ 35.49 $ 37.93 $ 22.58
Schedule of Performance Share Units Activity	Activity The following table shows our PSU activity for 2018 . GRANTS (IN THOUSANDS) WEIGHTED AVERAGE GRANT-DATE FAIR VALUE Nonvested at December 31, 2017 965 $ 30.87 Granted at target 343 35.49 Vested (112 ) 32.79 Forfeited (26 ) 37.93 Performance adjustment (128 ) $ 34.74 Nonvested at December 31, 2018 (1) 1,042 $ 31.52 (1) As of December 31, 2018, there were approximately 232 thousand PSUs that had met the requisite service period and will be released as identified in the grant terms.
Schedule of Stock Options Activity	Activity The following table shows our option unit activity for 2018 . OPTIONS (IN THOUSANDS) WEIGHTED AVERAGE EXERCISE PRICE WEIGHTED AVERAGE REMAINING CONTRACTUAL TERM (IN YEARS) AGGREGATE INTRINSIC VALUE (IN MILLIONS) Outstanding at December 31, 2017 8,487 $ 26.47 Exercised (2,025 ) $ 25.68 Forfeited or expired (96 ) $ 25.02 Outstanding at December 31, 2018 (1) 6,366 $ 26.75 5.33 $ 4 Exercisable at December 31, 2018 4,732 $ 27.14 4.78 $ 4 (1) As of December 31, 2018, there were approximately 573 thousand stock options that had met the requisite service period and will be released as identified in the grant terms.

CHARGES FOR INTEGRATION AND R_2

CHARGES FOR INTEGRATION AND RESTRUCTURING, CLOSURES AND ASSET IMPAIRMENTS (Tables)	12 Months Ended
	Dec. 31, 2018
Items Included in Our Charges for Integration and Restructuring, Closures, and Asset Impairments	Items Included in Our Charges for Integration and Restructuring, Closures and Asset Impairments DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Integration and restructuring charges related to our merger with Plum Creek: Termination benefits $ — $ 11 $ 54 Acceleration of share-based compensation related to qualifying terminations (Note 17) — — 21 Acceleration of pension benefits related to qualifying terminations (Note 10) — — 5 Professional services — 16 52 Other integration and restructuring costs — 7 14 Total integration and restructuring charges related to our merger with Plum Creek — 34 146 Charges related to closures and other restructuring activities 1 6 8 Impairment of long-lived assets 1 154 16 Total charges for integration and restructuring, closures and asset impairments $ 2 $ 194 $ 170

OTHER OPERATING COSTS (INCOME_2

OTHER OPERATING COSTS (INCOME), NET (Tables)	12 Months Ended
	Dec. 31, 2018
Various Income and Expense Items Included in Other Operating Costs (Income), Net	Various Income and Expense Items Included in Other Operating Costs (Income), Net DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Gain on disposition of nonstrategic assets (1) $ (5 ) $ (16 ) $ (60 ) Foreign exchange losses (gains), net (2) (3 ) (1 ) (6 ) Litigation expense, net 35 20 24 Gain on sale of timberlands (3) — (99 ) — Environmental remediation insurance recoveries (5 ) (42 ) — Other, net (4) 52 10 (11 ) Total other operating costs (income), net $ 74 $ (128 ) $ (53 ) (1) Gain on disposition of nonstrategic assets in 2016 included a $36 million pretax gain recognized in first quarter 2016 on the sale of our Federal Way, Washington headquarters campus. (2) Foreign exchange gains and losses result from changes in exchange rates primarily related to our U.S. dollar denominated cash and debt balances that are held by our Canadian subsidiary. (3) Gain on sale of 100,000 acres sold to Twin Creeks during Q4 2017. Refer to Note 9: Related Parties for further information. (4) "Other, net" includes environmental remediation charges. See Note 15: Legal Proceedings, Commitments and Contingencies for more information.

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2018
Domestic and Foreign Earnings from Continuing Operations Before Income Taxes	Domestic and Foreign Earnings from Continuing Operations Before Income Taxes DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Domestic earnings $ 556 $ 643 $ 353 Foreign earnings 251 73 151 Total earnings before income taxes $ 807 $ 716 $ 504
Provision (Benefit) for Income Taxes from Continuing Operations	Provision (Benefit) for Income Taxes from Continuing Operations DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Current: Federal $ (69 ) $ 10 $ 1 State (5 ) — 1 Foreign 61 82 11 Total current (13 ) 92 13 Deferred: Federal 45 61 37 State 12 (18 ) (3 ) Foreign 15 (1 ) 42 Total deferred 72 42 76 Total income tax provision (benefit) $ 59 $ 134 $ 89
Effective Income Tax Rate Applicable to Continuing Operations	Effective Income Tax Rate Applicable to Continuing Operations DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 U.S. federal statutory income tax $ 170 $ 250 $ 177 State income taxes, net of federal tax benefit 8 (2 ) (3 ) REIT income not subject to federal income tax (116 ) (198 ) (99 ) SDT settlement 21 — — Tax effect of U.S. corporate rate change — 74 — Voluntary pension contribution (41 ) — — Foreign taxes 15 54 (4 ) Repatriation of Canadian earnings — (22 ) 24 Other, net 2 (22 ) (6 ) Total income tax provision (benefit) $ 59 $ 134 $ 89 Effective income tax rate 7.3 % 18.8 % 17.6 %
Balance Sheet Classification of Deferred Income Tax Assets (Liabilities) Related to Continuing Operations	Balance Sheet Classification of Deferred Income Tax Assets (Liabilities) Related to Continuing Operations DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Net noncurrent deferred tax asset $ 15 $ 268 Net noncurrent deferred tax liability (43 ) — Net deferred tax asset (liability) $ (28 ) $ 268
Items Included in Our Deferred Income Tax Assets (Liabilities)	Items Included in Our Deferred Income Tax Assets (Liabilities) DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Deferred tax assets: Postretirement benefits $ 37 $ 50 Pension 75 306 State tax credits 51 56 Other reserves 13 38 Depletion 41 40 Excess interest 30 — Incentive compensation 20 23 Workers compensation 18 19 Net operating loss carryforwards 19 18 Other 83 70 Gross deferred tax assets 387 620 Valuation allowance (61 ) (63 ) Net deferred tax assets 326 557 Deferred tax liabilities: Property, plant and equipment (197 ) (154 ) Timber installment notes (116 ) (116 ) Other (41 ) (19 ) Net deferred tax liabilities (354 ) (289 ) Net deferred tax asset (liability) (28 ) 268
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits	Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, Balance at beginning of year $ 4 $ 6 Lapse of statute (1 ) (2 ) Balance at end of year $ 3 $ 4

GEOGRAPHIC AREAS (Tables)

GEOGRAPHIC AREAS (Tables)	12 Months Ended
	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales by Geographic Area	Sales by Geographic Area DOLLAR AMOUNTS IN MILLIONS 2018 2017 2016 Sales to unaffiliated customers: U.S. $ 6,365 $ 6,168 $ 5,451 Canada 519 472 341 Japan 410 352 369 China 120 107 108 Other foreign countries 62 97 96 Total $ 7,476 $ 7,196 $ 6,365 Export sales from the U.S.: Japan $ 338 $ 295 $ 314 China 113 102 103 Other foreign countries 153 148 98 Total $ 604 $ 545 $ 515
Long-Lived Assets by Geographic Area	Long-Lived Assets by Geographic Area DOLLAR AMOUNTS IN MILLIONS DECEMBER 31, DECEMBER 31, DECEMBER 31, U.S. $ 14,778 $ 14,922 $ 15,700 Canada 220 223 206 Other foreign countries — — 527 Total (1) $ 14,998 $ 15,145 $ 16,433 (1) Amounts for December 31, 2016, include assets from discontinued operations.

SELECTED QUARTERLY FINANCIAL _2

SELECTED QUARTERLY FINANCIAL INFORMATION (unaudited) (Table)	12 Months Ended
	Dec. 31, 2018
Key Quarterly Financial Data for the Last Two Years	Key Quarterly Financial Data for the Last Two Years DOLLAR AMOUNTS IN MILLIONS EXCEPT PER-SHARE FIGURES FIRST QUARTER SECOND QUARTER THIRD QUARTER FOURTH QUARTER FULL YEAR 2018: Net sales $ 1,865 $ 2,065 $ 1,910 $ 1,636 $ 7,476 Operating income from continuing operations 404 476 337 177 1,394 Earnings (loss) from continuing operations before income taxes 299 382 240 (114 ) 807 Net earnings (loss) 269 317 255 (93 ) 748 Basic and diluted net earnings (loss) per share 0.35 0.42 0.34 (0.12 ) 0.99 Dividends paid per share 0.32 0.32 0.34 0.34 1.32 2017: Net sales $ 1,693 $ 1,808 $ 1,872 $ 1,823 $ 7,196 Operating income from continuing operations 293 157 205 476 1,131 Earnings (loss) from continuing operations before income taxes 181 58 103 374 716 Net earnings (loss) 157 24 130 271 582 Basic and diluted net earnings (loss) per share 0.21 0.03 0.17 0.36 0.77 Dividends paid per share 0.31 0.31 0.31 0.32 1.25

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018
Reclassification of certain tax effects, due to tax law changes		$ (253)
Negative book cash balances		0
Adoption of new accounting pronouncement	$ (9)	$ (9)
Canada | Maximum
Term of timber lease		25 years
Canada | Minimum
Term of timber lease		15 years

BUSINESS SEGMENTS - Sales and C

BUSINESS SEGMENTS - Sales and Contribution (Charge) to Earnings (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers	$ 1,636	$ 1,910	$ 2,065	$ 1,865	$ 1,823	$ 1,872	$ 1,808	$ 1,693	$ 7,476	$ 7,196	$ 6,365
Contribution (charge) to earnings from continuing operations									1,182	1,109	1,892
Timberlands
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers									1,915	1,942	1,805
Wood Products
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers									5,255	4,974	4,334
Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers											6,365
Intersegment sales									0	0	0
Contribution (charge) to earnings from continuing operations									1,182	1,109	935
Operating segments | RE & ENR
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers									306	280	226
Operating segments | Continuing operations | Timberlands
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers									1,915	1,942	1,805
Intersegment sales									802	762	840
Contribution (charge) to earnings from continuing operations									583	532	499
Operating segments | Continuing operations | RE & ENR
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment sales									1	1	1
Contribution (charge) to earnings from continuing operations									127	146	55
Operating segments | Continuing operations | Wood Products
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers									5,255	4,974	4,334
Intersegment sales									0	0	68
Contribution (charge) to earnings from continuing operations									838	569	512
Intersegment eliminations | Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment sales									(803)	(763)	(909)
Unallocated Items | Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers									0	0	0
Contribution (charge) to earnings from continuing operations									$ (366)	$ (138)	$ (131)

BUSINESS SEGMENTS - Reconciliat

BUSINESS SEGMENTS - Reconciliation of Contribution to Earnings to Net Earnings (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Contribution (Charge) to Earnings From Segment to Net Earnings [Line Items]
Contribution (charge) to earnings from continuing operations									$ 1,182	$ 1,109	$ 1,892
Interest expense, net of capitalized interest(1)									(375)	(393)	(436)
Income before income taxes(1)									807	716	1,456
Income taxes(1)									(59)	(134)	(429)
Net earnings	$ (93)	$ 255	$ 317	$ 269	$ 271	$ 130	$ 24	$ 157	748	582	1,027
Continuing operations
Reconciliation of Contribution (Charge) to Earnings From Segment to Net Earnings [Line Items]
Contribution (charge) to earnings from continuing operations									1,182	1,109	935
Discontinued operations
Reconciliation of Contribution (Charge) to Earnings From Segment to Net Earnings [Line Items]
Contribution (charge) to earnings from continuing operations									$ 0	$ 0	$ 957

BUSINESS SEGMENTS - Total Asset

BUSINESS SEGMENTS - Total Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 17,249	$ 18,059
Operating segments | Timberlands and Real Estate & ENR
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	13,838	14,122
Operating segments | Wood Products
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	2,234	2,145
Unallocated Items
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 1,177	$ 1,792

BUSINESS SEGMENTS - Additional

BUSINESS SEGMENTS - Additional Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Other Significant Reconciling Item [Line Items]
Depreciation, depletion and amortization	$ 486	$ 521	$ 565
Charges for integration and restructuring, closures and asset impairments (Note 18)	2	194	170
Capital expenditures	427	419	425
Operating segments | Timberlands
Segment Reporting, Other Significant Reconciling Item [Line Items]
Depreciation, depletion and amortization	319	356	366
Charges for integration and restructuring, closures and asset impairments (Note 18)	0	147	0
Capital expenditures	117	115	116
Operating segments | RE & ENR
Segment Reporting, Other Significant Reconciling Item [Line Items]
Depreciation, depletion and amortization	14	15	13
Charges for integration and restructuring, closures and asset impairments (Note 18)	0	0	15
Capital expenditures	0	2	1
Operating segments | Wood Products
Segment Reporting, Other Significant Reconciling Item [Line Items]
Depreciation, depletion and amortization	149	145	129
Charges for integration and restructuring, closures and asset impairments (Note 18)	2	13	7
Capital expenditures	306	299	297
Unallocated Items
Segment Reporting, Other Significant Reconciling Item [Line Items]
Depreciation, depletion and amortization	4	5	4
Charges for integration and restructuring, closures and asset impairments (Note 18)	0	34	148
Capital expenditures	$ 4	$ 3	11
Continuing operations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Depreciation, depletion and amortization			$ 512

REVENUE RECOGNITION (Details)

REVENUE RECOGNITION (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue from External Customer
Revenues	$ 1,636	$ 1,910	$ 2,065	$ 1,865	$ 1,823	$ 1,872	$ 1,808	$ 1,693	$ 7,476	$ 7,196	$ 6,365
Timberlands
Revenue from External Customer
Revenues									1,915	1,942	1,805
Timberlands | Delivered logs
Revenue from External Customer
Revenues									1,752	1,685	1,560
Timberlands | Stumpage and pay-as-cut timber
Revenue from External Customer
Revenues									59	73	85
Timberlands | Recreational and other lease revenue
Revenue from External Customer
Revenues									59	59	44
Timberlands | Other
Revenue from External Customer
Revenues									45	125	116
Timberlands | West | Delivered logs
Revenue from External Customer
Revenues									987	915	865
Timberlands | South | Delivered logs
Revenue from External Customer
Revenues									625	616	566
Timberlands | North | Delivered logs
Revenue from External Customer
Revenues									99	95	91
Timberlands | Other | Delivered logs
Revenue from External Customer
Revenues									41	59	38
Timberlands | Domestic sales | West | Delivered logs
Revenue from External Customer
Revenues									503	473	410
Timberlands | Export Sales | West | Delivered logs
Revenue from External Customer
Revenues									484	442	455
RE & ENR | Real estate sales
Revenue from External Customer
Revenues									229	208	172
RE & ENR | Energy and natural resources products [Member]
Revenue from External Customer
Revenues									77	72	54
Wood Products
Revenue from External Customer
Revenues									5,255	4,974	4,334
Wood Products | Structural lumber
Revenue from External Customer
Revenues									2,258	2,058	1,839
Wood Products | Oriented Strand Board
Revenue from External Customer
Revenues									891	904	707
Wood Products | Engineered Solid Section
Revenue from External Customer
Revenues									521	500	450
Wood Products | Engineered I-joists
Revenue from External Customer
Revenues									336	336	290
Wood Products | Softwood Plywood
Revenue from External Customer
Revenues									200	176	174
Wood Products | Medium density fiberboard
Revenue from External Customer
Revenues									177	183	158
Wood Products | Complementary building products
Revenue from External Customer
Revenues									584	541	515
Wood Products | Other
Revenue from External Customer
Revenues									$ 288	$ 276	201
Continuing operations
Revenue from External Customer
Revenues											$ 6,365

DISCONTINUED OPERATIONS AND O_3

DISCONTINUED OPERATIONS AND OTHER DIVESTITURES - Components of the Net Gain on CF Divestitures (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds, net of cash and cash equivalents disposed of	$ 0	$ 403	$ 2,486
Cellulose Fibers
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds, net of cash and cash equivalents disposed of			2,486
Net book value of assets and liabilities disposed of			(1,678)
Transaction costs, net of reimbursement			(19)
Net book value of contributed assets and transaction costs, net of reimbursement			(1,697)
Pretax gain on Cellulose Fibers divestitures			789
Income taxes			(243)
Net gain on Cellulose Fibers divestitures			$ 546

DISCONTINUED OPERATIONS AND O_4

DISCONTINUED OPERATIONS AND OTHER DIVESTITURES - Sales and Net Earnings from Discontinued Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total net sales			$ 1,537
Costs of sales			1,283
Gross margin			254
Selling expenses			12
General and administrative expenses			29
Research and development expenses			5
Charges for integration and restructuring, closures and asset impairments(2)			63
Other operating income, net			(27)
Operating income			172
Equity loss from joint venture			(4)
Interest expense, net of capitalized interest			(5)
Earnings from discontinued operations before income taxes			163
Income taxes			(97)
Net earnings from operations			66
Net earnings from discontinued operations	$ 0	$ 0	612
Cellulose Fibers
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain on Cellulose Fibers divestitures			$ 546

DISCONTINUED OPERATIONS AND O_5

DISCONTINUED OPERATIONS AND OTHER DIVESTITURES - Cash Flows from Discontinued Operations (Details) - Cellulose Fibers $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net cash provided by operating activities	$ 196
Net cash provided by investing activities	$ 2,356

DISCONTINUED OPERATIONS AND O_6

DISCONTINUED OPERATIONS AND OTHER DIVESTITURES - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposition of discontinued and other operations		$ 0	$ 403	$ 2,486
Uruguayan Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposition of discontinued and other operations	$ 403
Uruguay Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets			0
Liabilities			0
Cellulose Fibers
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposition of discontinued and other operations				2,486
Pretax gain on Cellulose Fibers divestitures				789
Proceeds from divestiture used to repay debt				1,700
Gain on divestiture				546
Assets			0	0
Liabilities			$ 0	0
Pulp
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposition of discontinued and other operations				2,200
Liquid Packaging Board
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposition of discontinued and other operations				285
NORPAC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposition of discontinued and other operations				42
NORPAC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity method investment, ownership percentage					50.00%
Amount received from related party transaction				$ 126

MERGER WITH PLUM CREEK Unaudite

MERGER WITH PLUM CREEK Unaudited Proforma (Details) - Plum Creek $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)$ / shares
Business Acquisition [Line Items]
Net sales | $	$ 6,525
Net earnings from continuing operations attributable to Weyerhaeuser common shareholders | $	$ 519
Net earnings from continuing operations per share attributable to Weyerhaeuser common shareholders, basic | $ / shares	$ 0.69
Net earnings from continuing operations per share attributable to Weyerhaeuser common shareholders, diluted | $ / shares	$ 0.68

MERGER WITH PLUM CREEK Recogniz

MERGER WITH PLUM CREEK Recognized Identified Assets Acquired and Liabilities Assumed (Details) - Plum Creek $ in Billions	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Total assets acquired	$ 10
Total liabilities assumed	$ 3.6

MERGER WITH PLUM CREEK Addition

MERGER WITH PLUM CREEK Additional Information (Details) - Plum Creek $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Total assets acquired	$ 10,000
Estimated consideration transferred	6,400
Total liabilities assumed	3,600
Non-recurring merger-related costs	$ 155

NET EARNINGS PER SHARE - Schedu

NET EARNINGS PER SHARE - Schedule of Earnings per Share, Basic and Diluted (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Weighted average number of outstanding shares - basic	754,556	753,085	718,560
Dilutive potential common shares	2,271	3,581	3,841
Weighted average number of outstanding common shares - diluted	756,827	756,666	722,401
Stock options
Dilutive potential common shares	1,310	2,571	2,672
Restricted stock units
Dilutive potential common shares	566	582	756
Performance share units
Dilutive potential common shares	395	428	413

NET EARNINGS PER SHARE - Potent

NET EARNINGS PER SHARE - Potential Shares Not Included in the Computation of Diluted Earnings Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential shares not included in the computation of diluted earnings per share	2,402	1,351	1,462
Performance share units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential shares not included in the computation of diluted earnings per share	1,080	799	384

NET EARNINGS PER SHARE - Additi

NET EARNINGS PER SHARE - Additional Information (Details) - $ / shares	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic earnings per share attributable to Weyerhaeuser common shareholders	$ (0.12)	$ 0.34	$ 0.42	$ 0.35	$ 0.36	$ 0.17	$ 0.03	$ 0.21	$ 0.99	$ 0.77	$ 1.40
Diluted earnings per share attributable to Weyerhaeuser common shareholders									$ 0.99	$ 0.77	$ 1.39

INVENTORIES - Inventories as of

INVENTORIES - Inventories as of the End of Our Last Two Years (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Inventory [Line Items]
Total	$ 389	$ 383
Logs
Inventory [Line Items]
LIFO inventories	11	17
FIFO or moving average cost inventories	35	38
Lumber, plywood, panels, and fiberboard
Inventory [Line Items]
LIFO inventories	75	66
Lumber, plywood, panels, fiberboard and engineered wood products
Inventory [Line Items]
FIFO or moving average cost inventories	86	91
Other products
Inventory [Line Items]
LIFO inventories	10	10
FIFO or moving average cost inventories	83	77
Materials and supplies
Inventory [Line Items]
FIFO or moving average cost inventories	$ 89	$ 84

INVENTORIES - Additional Inform

INVENTORIES - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Inventory [Line Items]
Increase in inventory amount if FIFO would have been used	$ 79	$ 70

PROPERTY AND EQUIPMENT - Carryi

PROPERTY AND EQUIPMENT - Carrying Value of Property and Equipment and Estimated Service Lives (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property and Equipment [Line Items]
Property and equipment, at cost	$ 5,233	$ 4,956
Accumulated depreciation and amortization	(3,376)	(3,338)
Property and equipment, net	1,857	1,618
Land
Property and Equipment [Line Items]
Property and equipment, at cost	87	88
Buildings and improvements
Property and Equipment [Line Items]
Property and equipment, at cost	942	867
Machinery and equipment
Property and Equipment [Line Items]
Property and equipment, at cost	3,240	3,037
Roads
Property and Equipment [Line Items]
Property and equipment, at cost	785	782
Other
Property and Equipment [Line Items]
Property and equipment, at cost	$ 179	$ 182
Minimum | Buildings and improvements
Property and Equipment [Line Items]
Estimated service lives	15 years
Minimum | Machinery and equipment
Property and Equipment [Line Items]
Estimated service lives	5 years
Minimum | Roads
Property and Equipment [Line Items]
Estimated service lives	10 years
Minimum | Other
Property and Equipment [Line Items]
Estimated service lives	3 years
Maximum | Buildings and improvements
Property and Equipment [Line Items]
Estimated service lives	40 years
Maximum | Machinery and equipment
Property and Equipment [Line Items]
Estimated service lives	25 years
Maximum | Roads
Property and Equipment [Line Items]
Estimated service lives	35 years
Maximum | Other
Property and Equipment [Line Items]
Estimated service lives	10 years

PROPERTY AND EQUIPMENT - Additi

PROPERTY AND EQUIPMENT - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property and Equipment [Line Items]
Depreciation expense, excluding discontinued operations	$ 197	$ 206	$ 198
Buildings and improvements | Minimum
Property and Equipment [Line Items]
Estimated service lives	15 years
Buildings and improvements | Maximum
Property and Equipment [Line Items]
Estimated service lives	40 years

RELATED PARTIES - Schedule of C

RELATED PARTIES - Schedule of Changes in Deposit of Timberlands (Details) - Twin Creeks Venture $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Related Party Transaction [Line Items]
Beginning Balance	$ 426
Lease payments to Twin Creeks Venture	(8)
Distributions from Twin Creeks Venture	2
Recognition of contributed timberlands	(420)
Ending Balance	$ 0

RELATED PARTIES - Additional In

RELATED PARTIES - Additional Information (Details) $ in Millions	Apr. 01, 2016USD ($)a	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)a	Dec. 31, 2020	Dec. 31, 2018USD ($)Rate	Dec. 31, 2017USD ($)a	Dec. 31, 2016USD ($)
Related Party Transaction [Line Items]
Gain on sale of timberlands					$ 0	$ (99)	$ 0
Proceeds from sale of Southern timberlands					0	203	0
Proceeds from contribution of timberlands to related party (Note 9)					0	0	440
Proceeds from redemption of ownership interest in related party					0	108	0
Interest expense					375	393	431
Real Estate Development Ventures
Related Party Transaction [Line Items]
Expiration of joint venture agreement				2,020
Equity Method Investments			$ 31			$ 31
Proceeds from Equity Method Investment, Distribution, Return of Capital					$ 1
Twin Creeks Venture
Related Party Transaction [Line Items]
Sale of Timberland acreage | a			100,000			100,000
Gain on sale of timberlands			$ (99)
Proceeds from sale of Southern timberlands			$ 203
Contributed acres of timberlands to venture | a	260,000
Agreed-upon value of acres contributed	$ 560
Proceeds from contribution of timberlands to related party (Note 9)	$ 440
Ownership interest						21.00%
Proceeds from redemption of ownership interest in related party						$ 108
Other partner ownership interest			79.00%			79.00%
Guaranteed annual return						3.00%
Percentage of profit in excess of guaranteed annual return						75.00%
Twin Creeks Venture | Georgia
Related Party Transaction [Line Items]
Sale of Timberland acreage | a			20,000			20,000
Twin Creeks Venture | Mississippi
Related Party Transaction [Line Items]
Sale of Timberland acreage | a			80,000			80,000
Class A Properties | Real Estate Development Ventures
Related Party Transaction [Line Items]
Equity method investment, ownership percentage		3.00%			3.00%
Class B Properties | Real Estate Development Ventures
Related Party Transaction [Line Items]
Equity method investment, ownership percentage		50.00%			50.00%
Monetization SPEs
Related Party Transaction [Line Items]
Weighted average interest rate on SPE long-term notes | Rate					5.60%
Monetization SPEs | Long-Term Debt due 2018 [Member]
Related Party Transaction [Line Items]
Payments related to liabilities from our monetized SPEs		$ 209
Debt, Maturity Date					Dec. 31, 2018
Monetization SPEs | Long-term notes due 2019
Related Party Transaction [Line Items]
SPE long-term notes		302			$ 302
Debt, Maturity Date					Sep. 30, 2019
Buyer-sponsored SPEs
Related Party Transaction [Line Items]
Weighted average interest rate on SPE financial investments | Rate					5.50%
Buyer-sponsored SPEs | SPE restricted investment due in 2019
Related Party Transaction [Line Items]
SPE restricted financial investments		253			$ 253
Investment Maturity Date					Mar. 31, 2019
Buyer-sponsored SPEs | SPE restricted investment due in 2020
Related Party Transaction [Line Items]
SPE restricted financial investments		$ 362			$ 362
Investment Maturity Date					Mar. 31, 2020
SPEs
Related Party Transaction [Line Items]
Interest expense					$ 29	$ 29	29
Interest income					$ 34	$ 34	$ 34

PENSION AND OTHER POSTRETIREM_3

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Funded Status of Our Plans (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 4,930	$ 5,514	$ 5,351
Projected benefit obligations	(5,263)	(6,795)	(6,469)
Funded status	(333)	(1,281)
Noncurrent assets	74	45
Current liabilities	(18)	(21)
Noncurrent liabilities	(389)	(1,305)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	18	0	0
Projected benefit obligations	(166)	(200)	$ (225)
Funded status	(148)	(200)
Noncurrent assets	0	0
Current liabilities	(10)	(19)
Noncurrent liabilities	$ (138)	$ (181)

PENSION AND OTHER POSTRETIREM_4

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Changes in Fair Value of Plan Assets (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Adjustment for final fair value of plan assets		$ 44
Pension
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year (estimated)			$ 5,514	$ 5,351
Adjustment for final fair value of plan assets			44	18
Actual return on plan assets			123	553
Foreign currency translation			(73)	59
Employer contributions and benefit payments			345	57
Plan participants’ contributions			0	0
Plan transfers			1	3
Benefits paid (includes lump sum settlements)	$ (664)		(1,024)	(527)
Fair value of plan assets at end of year (estimated)	4,930		4,930	5,514
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year (estimated)			0	0
Adjustment for final fair value of plan assets			0	0
Actual return on plan assets			0	0
Foreign currency translation			0	0
Employer contributions and benefit payments			36	20
Plan participants’ contributions			4	6
Plan transfers			0	0
Benefits paid (includes lump sum settlements)			(22)	(26)
Fair value of plan assets at end of year (estimated)	$ 18		$ 18	$ 0

PENSION AND OTHER POSTRETIREM_5

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Changes in Projected Benefit Obligations of Our Pension and Other Postretirement Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation beginning of year	$ 6,795	$ 6,469
Service cost	37	35	$ 48
Interest cost	236	264	277
Plan participants’ contributions	0	0
Actuarial (gains) losses	(718)	489
Foreign currency translation	(69)	59
Benefits paid (includes lump sum settlements)	(1,024)	(527)
Plan amendments and other	5	3
Plan transfers	1	3
Projected benefit obligation, end of year	5,263	6,795	6,469
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation beginning of year	200	225
Service cost	0	0	0
Interest cost	7	8	8
Plan participants’ contributions	4	6
Actuarial (gains) losses	(18)	(18)
Foreign currency translation	(5)	5
Benefits paid (includes lump sum settlements)	(22)	(26)
Plan amendments and other	0	0
Plan transfers	0	0
Projected benefit obligation, end of year	$ 166	$ 200	$ 225

PENSION AND OTHER POSTRETIREM_6

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Assets Within Our U.S. and Canadian Qualified and Registered Pension Plans (Details) - Qualified and Registered Plans [Member]	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Assets invested in pension plan, allocation percentage	(100.00%)	(100.00%)
Cash and short-term investments
Defined Benefit Plan Disclosure [Line Items]
Assets invested in pension plan, allocation percentage	(5.80%)	(10.60%)
Fixed income investments, Corporate
Defined Benefit Plan Disclosure [Line Items]
Assets invested in pension plan, allocation percentage	(21.50%)	(0.00%)
Government
Defined Benefit Plan Disclosure [Line Items]
Assets invested in pension plan, allocation percentage	(8.60%)	(0.00%)
Hedge funds and related investments
Defined Benefit Plan Disclosure [Line Items]
Assets invested in pension plan, allocation percentage	(36.90%)	(58.80%)
Private equity and related investments
Defined Benefit Plan Disclosure [Line Items]
Assets invested in pension plan, allocation percentage	(21.90%)	(22.20%)
Derivative instruments, net
Defined Benefit Plan Disclosure [Line Items]
Assets invested in pension plan, allocation percentage	(5.60%)	(8.70%)
Accrued liabilities
Defined Benefit Plan Disclosure [Line Items]
Assets invested in pension plan, allocation percentage	(0.30%)	(0.30%)

PENSION AND OTHER POSTRETIREM_7

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Net Pension Plan Assets, by Fair Value Hiearchy (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 4,920	$ 5,502
Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	330	557	$ 455
Hedge funds and related investments | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	10	4
Private equity and related investments | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	65	102	75
Accrued liabilities, net | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(17)	(16)
Pension
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,930	5,514	$ 5,351
U.S. | Fixed Income Investments, Government [Member] | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	426
U.S. | Fixed Income Investments, Government [Member] | Fair Value, Inputs, Level 1 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
U.S. | Fixed Income Investments, Government [Member] | Fair Value, Inputs, Level 2 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	426
U.S. | Fixed Income Investments, Government [Member] | Fair Value, Inputs, Level 3 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
U.S. | Cash and short-term investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	287	582
U.S. | Cash and short-term investments | Fair Value, Inputs, Level 1 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	275	580
U.S. | Cash and short-term investments | Fair Value, Inputs, Level 2 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	2
U.S. | Cash and short-term investments | Fair Value, Inputs, Level 3 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Common and preferred stock | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1
U.S. | Common and preferred stock | Fair Value, Inputs, Level 1 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1
U.S. | Common and preferred stock | Fair Value, Inputs, Level 2 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
U.S. | Common and preferred stock | Fair Value, Inputs, Level 3 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
U.S. | Fixed Income Investments [Member] | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,054
U.S. | Fixed Income Investments [Member] | Fair Value, Inputs, Level 1 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
U.S. | Fixed Income Investments [Member] | Fair Value, Inputs, Level 2 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,054
U.S. | Fixed Income Investments [Member] | Fair Value, Inputs, Level 3 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
U.S. | Hedge funds and related investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,814	3,237
U.S. | Hedge funds and related investments | Fair Value, Inputs, Level 1 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	59
U.S. | Hedge funds and related investments | Fair Value, Inputs, Level 2 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Hedge funds and related investments | Fair Value, Inputs, Level 3 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	10
U.S. | Private equity and related investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,079	1,222
U.S. | Private equity and related investments | Fair Value, Inputs, Level 1 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Private equity and related investments | Fair Value, Inputs, Level 2 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Private equity and related investments | Fair Value, Inputs, Level 3 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	65	102
U.S. | Derivative financial instruments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	277	476
U.S. | Derivative financial instruments | Fair Value, Inputs, Level 1 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Derivative financial instruments | Fair Value, Inputs, Level 2 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15	31
U.S. | Derivative financial instruments | Fair Value, Inputs, Level 3 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	262	445
U.S. | Investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,937	5,518
U.S. | Investments | Fair Value, Inputs, Level 1 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	275	640
U.S. | Investments | Fair Value, Inputs, Level 2 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,507	33
U.S. | Investments | Fair Value, Inputs, Level 3 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	330	557
U.S. | Fixed Income Investments, Government [Member] | Hedge funds and related investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
U.S. | Net asset value [Member] | Cash and short-term investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Net asset value [Member] | Common and preferred stock | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
U.S. | Net asset value [Member] | Hedge funds and related investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,811	3,168
U.S. | Net asset value [Member] | Private equity and related investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,014	1,120
U.S. | Net asset value [Member] | Derivative financial instruments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Net asset value [Member] | Investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,825	4,288
U.S. | Fixed Income Investments [Member] | Hedge funds and related investments | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Canada | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	12
Canada | Fair Value, Inputs, Level 1 | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	12
Canada | Fair Value, Inputs, Level 2 | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Canada | Fair Value, Inputs, Level 3 | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Canada | Cash and short-term investments | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	6
Canada | Cash and short-term investments | Fair Value, Inputs, Level 1 | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	6
Canada | Cash and short-term investments | Fair Value, Inputs, Level 2 | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Canada | Cash and short-term investments | Fair Value, Inputs, Level 3 | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Canada | Common and preferred stock | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	6
Canada | Common and preferred stock | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Canada | Common and preferred stock | Fair Value, Inputs, Level 1 | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	6
Canada | Common and preferred stock | Fair Value, Inputs, Level 1 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Canada | Common and preferred stock | Fair Value, Inputs, Level 2 | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Canada | Common and preferred stock | Fair Value, Inputs, Level 2 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Canada | Common and preferred stock | Fair Value, Inputs, Level 3 | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Canada | Common and preferred stock | Fair Value, Inputs, Level 3 | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Canada | Net asset value [Member] | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Canada | Net asset value [Member] | Cash and short-term investments | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Canada | Net asset value [Member] | Common and preferred stock | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	$ 0
Canada | Net asset value [Member] | Common and preferred stock | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0

PENSION AND OTHER POSTRETIREM_8

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Reconciliation of Pension Plan Assets Measured at Level 3 Fair Value (Details) - Fair Value, Inputs, Level 3 - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year (estimated)	$ 557	$ 455
Net realized gains (losses)	238	(16)
Net change in unrealized gains (losses)	(188)	110
Purchases	5	14
Sales	(2)	(1)
Settlements	(237)	(13)
Transfers into Level 3	18	25
Transfers out of Level 3	(61)	(17)
Fair value of plan assets at end of year (estimated)	330	557
Hedge funds and related investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year (estimated)	10	4
Net realized gains (losses)	0	(1)
Net change in unrealized gains (losses)	1	2
Purchases	0	0
Sales	0	(1)
Settlements	0	0
Transfers into Level 3	0	6
Transfers out of Level 3	(8)	0
Fair value of plan assets at end of year (estimated)	3	10
Private equity and related investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year (estimated)	102	75
Net realized gains (losses)	0	(30)
Net change in unrealized gains (losses)	(5)	41
Purchases	5	14
Sales	(2)	0
Settlements	0	0
Transfers into Level 3	18	19
Transfers out of Level 3	(53)	(17)
Fair value of plan assets at end of year (estimated)	65	102
Derivative instruments, net
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year (estimated)	445	376
Net realized gains (losses)	238	15
Net change in unrealized gains (losses)	(184)	67
Purchases	0	0
Sales	0	0
Settlements	(237)	(13)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Fair value of plan assets at end of year (estimated)	$ 262	$ 445

PENSION AND OTHER POSTRETIREM_9

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Fair Value and Aggregate Notional Amount of the Derivative Instruments Held by our Pension Trusts (Details) - Pension - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Derivatives, fair value, net	$ 277	$ 476
Derivative, notional amount	1,644	3,357
Equity and fixed income index derivatives, net
Defined Benefit Plan Disclosure [Line Items]
Derivatives, fair value, net	0	19
Derivative, notional amount	0	501
Foreign currency derivatives, net
Defined Benefit Plan Disclosure [Line Items]
Derivatives, fair value, net	0	12
Derivative, notional amount	13	1,413
Future [Member]
Defined Benefit Plan Disclosure [Line Items]
Derivatives, fair value, net	15	0
Derivative, notional amount	1,073	0
Total return swaps, net
Defined Benefit Plan Disclosure [Line Items]
Derivatives, fair value, net	262	445
Derivative, notional amount	$ 558	$ 1,443

PENSION AND OTHER POSTRETIRE_10

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Rates We Use in Estimating Our Benefit Obligations (Details) - Pension	12 Months Ended
	Dec. 31, 2018Rate	Dec. 31, 2017Rate
Defined Benefit Plan Disclosure [Line Items]
Lump sum distribution election	60.00%	60.00%
U.S.
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	4.40%	3.70%
Canada
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	3.70%	3.50%
Salaried | Canada
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3.25%	3.25%
Hourly | Canada
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3.00%	3.00%
Minimum | Salaried | U.S.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	2.00%	2.00%
Minimum | Hourly | U.S.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	2.30%	2.30%
Maximum | Salaried | U.S.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	13.00%	13.00%
Maximum | Hourly | U.S.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	13.00%	13.00%

PENSION AND OTHER POSTRETIRE_11

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Rates Used to Estimate Our Net Periodic Benefit Costs (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018Rate	Dec. 31, 2017Rate	Dec. 31, 2016Rate
Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	7.00%	3.50%	3.50%	3.50%
Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	7.00%	8.00%
Canada
Defined Benefit Plan Disclosure [Line Items]
Discount rates, net periodic benefit cost		3.50%	3.70%
Pension | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets		8.00%	8.00%	9.00%
Pension | Plum Creek | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets			7.00%
Pension | U.S.
Defined Benefit Plan Disclosure [Line Items]
Discount rates, net periodic benefit cost		3.70%	4.30%	4.50%
Pension | U.S. | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Lump sum distributions election(2)		60.00%	60.00%	60.00%
Pension | Canada
Defined Benefit Plan Disclosure [Line Items]
Discount rates, net periodic benefit cost				4.00%
Pension | Salaried | Canada
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase		3.25%	3.50%	3.50%
Pension | Hourly | Canada
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase		3.00%	3.25%	3.25%
Minimum | Pension | Salaried | U.S.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase		2.00%	2.00%	2.00%
Minimum | Pension | Hourly | U.S.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase		2.30%	2.30%	2.30%
Maximum | Pension | Salaried | U.S.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase		13.00%	13.00%	13.00%
Maximum | Pension | Hourly | U.S.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase		13.00%	13.00%	13.00%

PENSION AND OTHER POSTRETIRE_12

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Assumptions We Use in Estimating Health Care Benefit Costs (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
U.S.
Defined Benefit Plan Disclosure [Line Items]
Rate that the cost trend rate gradually declines to	4.50%	4.50%
Year the cost trend rate is reached	2,037	2,037
Canada
Defined Benefit Plan Disclosure [Line Items]
Rate that the cost trend rate gradually declines to	4.00%	4.30%
Year the cost trend rate is reached	2,039	2,028
Next year [Member] | U.S. | Health Reimbursement Account [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year	4.50%	4.50%
Next year [Member] | U.S. | Pre Medicare [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year	7.80%	8.40%
Next year [Member] | Canada
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year	4.90%	5.10%

PENSION AND OTHER POSTRETIRE_13

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Effect of a One Percent Change in Health Care Costs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest cost components on 1 percent increase in health care costs (less than)	$ 1
Effect on total service and interest cost components on 1 percent decrease in health care costs (less than)	(1)
Effect on accumulated postretirement benefit obligation on 1 percent increase in health care costs	5
Effect on accumulated postretirement benefit obligation on 1 percent decrease in health care costs	$ (4)

PENSION AND OTHER POSTRETIRE_14

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost			$ 37	$ 35	$ 48
Interest cost			236	264	277
Expected return on plan assets			(399)	(409)	(495)
Amortization of actuarial loss			225	195	156
Amortization of prior service cost (credit)			3	4	4
Defined Benefit Plan, Plan Assets, Payment for Settlement	$ 200	$ 450		0	0
Net periodic benefit cost (credit)			302	89	(5)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost			0	0	0
Interest cost			7	8	8
Expected return on plan assets			0	0	0
Amortization of actuarial loss			8	8	9
Amortization of prior service cost (credit)			(8)	(8)	(7)
Defined Benefit Plan, Plan Assets, Payment for Settlement	$ 0			0	0
Net periodic benefit cost (credit)			7	8	10
Plum Creek | Pension
Defined Benefit Plan Disclosure [Line Items]
Change in control enhanced benefits			0	0	5
Plum Creek | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Change in control enhanced benefits			$ 0	$ 0	0
Discontinued operations | Cellulose Fibers | Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost					$ 13

PENSION AND OTHER POSTRETIRE_15

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Estimated Amortization from Cumulative Other Comprehensive Loss (Details) $ in Millions	Dec. 31, 2018USD ($)
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 115
Prior service cost (credit)	3
Net effect cost	118
Pension
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	108
Prior service cost (credit)	4
Net effect cost	112
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	7
Prior service cost (credit)	(1)
Net effect cost	$ 6

PENSION AND OTHER POSTRETIRE_16

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Estimated Projected Benefit Payments for the Next 10 Years (Details) $ in Millions	Dec. 31, 2018USD ($)
Pension
Defined Benefit Plan Disclosure [Line Items]
Expected Future Benefit Payments in 2019	$ 272
Expected Future Benefit Payments in 2020	233
Expected Future Benefit Payments in 2021	231
Expected Future Benefit Payments in 2022	232
Expected Future Benefit Payments in 2023	234
Expected Future Benefit Payments in 2024-2028	1,161
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected Future Benefit Payments in 2019	17
Expected Future Benefit Payments in 2020	16
Expected Future Benefit Payments in 2021	15
Expected Future Benefit Payments in 2022	14
Expected Future Benefit Payments in 2023	14
Expected Future Benefit Payments in 2024-2028	$ 57

PENSION AND OTHER POSTRETIRE_17

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Additional Information (Details) - USD ($)	3 Months Ended			12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Period Increase (Decrease)			$ 44,000,000
Pension plans with accumulated benefit obligations greater than plan assets, projected benefit obligations	$ 4,500,000,000				$ 4,500,000,000	$ 5,900,000,000
Pension plans with accumulated benefit obligations greater than plan assets, accumulated benefit obligations	4,400,000,000				4,400,000,000	5,900,000,000
Pension plans with accumulated benefit obligations greater than plan assets, fair value of assets	4,100,000,000				4,100,000,000	4,600,000,000
Accumulated benefit obligation for all defined benefit pension plans	5,200,000,000				5,200,000,000	6,700,000,000
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)			155,000,000
Defined Benefit Plan Funded Status Period Increase Decrease			$ 199,000,000
Qualified Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits		$ 300,000,000
Employer contributions and benefit payments					$ 22,000,000	$ 21,000,000	$ 27,000,000
Defined benefit plan, required contribution					0
Plan annuity transfer				$ (1,500,000,000)
Non Qualified Pension Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions and benefit payments					$ 19,000,000
Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets				7.00%	3.50%	3.50%	3.50%
Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,920,000,000				$ 4,920,000,000	$ 5,502,000,000
Expected return on plan assets				7.00%	8.00%
U.S. | Non Qualified Pension Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to benefit plans during 2018	16,000,000				$ 16,000,000
Canada
Defined Benefit Plan Disclosure [Line Items]
Discount rates, net periodic benefit cost					3.50%	3.70%
Canada | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,000,000				$ 10,000,000	$ 12,000,000
Employer contributions and benefit payments					2,000,000
Expected contribution to benefit plans during 2018	3,000,000				3,000,000
Canada | Registered Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions and benefit payments					22,000,000
Expected contribution to benefit plans during 2018	17,000,000				17,000,000
Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	330,000,000				330,000,000	557,000,000	$ 455,000,000
Fair Value, Inputs, Level 3 | Canada | Non Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0				0	0
Pension
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Period Increase (Decrease)					44,000,000	18,000,000
Defined Benefit Plan, Plan Assets, Benefits Paid	664,000,000				1,024,000,000	527,000,000
Defined Benefit Plan, Plan Assets, Payment for Settlement	200,000,000			$ 450,000,000		0	0
Fair value of plan assets	$ 4,930,000,000				4,930,000,000	5,514,000,000	$ 5,351,000,000
Employer contributions and benefit payments					345,000,000	57,000,000
Plan annuity transfer					$ (1,000,000)	$ (3,000,000)
Pension | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets					8.00%	8.00%	9.00%
Pension | U.S.
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	4.40%				4.40%	3.70%
Discount rates, net periodic benefit cost					3.70%	4.30%	4.50%
Pension | Canada
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	3.70%				3.70%	3.50%
Discount rates, net periodic benefit cost							4.00%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Period Increase (Decrease)					$ 0	$ 0
Defined Benefit Plan, Plan Assets, Benefits Paid					22,000,000	26,000,000
Defined Benefit Plan, Plan Assets, Payment for Settlement	$ 0					0	$ 0
Fair value of plan assets	18,000,000				18,000,000	0	$ 0
Employer contributions and benefit payments					36,000,000	20,000,000
Expected contribution to benefit plans during 2018	$ 23,000,000				23,000,000
Plan annuity transfer					$ 0	$ 0
Other Postretirement Benefits | U.S.
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	4.20%				4.20%	3.50%
Discount rates, net periodic benefit cost					3.50%	3.70%	4.00%
Other Postretirement Benefits | Canada
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	3.70%				3.70%	3.40%
Discount rates, net periodic benefit cost					3.40%	3.60%	3.90%
Other Postretirement Benefits | Collective Bargaining Arrangement
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to benefit plans during 2018	$ 6,000,000				$ 6,000,000
Plum Creek | Pension
Defined Benefit Plan Disclosure [Line Items]
Change in control enhanced benefits					0	$ 0	$ 5,000,000
Plum Creek | Pension | Qualified and Registered Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets						7.00%
Plum Creek | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Change in control enhanced benefits					$ 0	$ 0	$ 0
Next year [Member] | U.S. | Pre Medicare [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year	7.80%				7.80%	8.40%
Next year [Member] | U.S. | Health Reimbursement Account [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year	4.50%				4.50%	4.50%
Next year [Member] | Canada
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year	4.90%				4.90%	5.10%

ACCRUED LIABILITIES (Details)

ACCRUED LIABILITIES (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accrued compensation and employee benefit costs	$ 192	$ 223
Accrued Taxes Payable	30	43
Customer rebates, volume discounts and deferred income	99	96
Interest	109	111
Product remediation accrual (Note 19)	2	98
Other	58	74
Total	$ 490	$ 645

LINES OF CREDIT - Other Letters

LINES OF CREDIT - Other Letters of Credit and Surety Bonds (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Letters of credit	$ 38	$ 37
Surety bonds	$ 123	$ 134

LINES OF CREDIT - Additional In

LINES OF CREDIT - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity		$ 1,500
Line of Credit Facility, Expiration Date	Mar. 31, 2022
Line of credit, amount outstanding	$ 425
Line of Credit Facility, Remaining Borrowing Capacity	1,075
Compensating balance requirments for our letters of credit	$ 6
Prior Credit Facility
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity			$ 1,000
Line of Credit Facility, Expiration Date		Sep. 30, 2018

LONG-TERM DEBT - Long-Term Debt

LONG-TERM DEBT - Long-Term Debt by Types and Interest Rates (Includes Current Portion) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Other	$ 1	$ 1
Long-term debt, before unamortized discounts	5,933	6,008
Less unamortized discounts	(5)	(5)
Less unamortized debt expense	(9)	(11)
Total	5,919	5,992
Portion due within one year	$ 500	62
Debt, maturity date	Mar. 31, 2022
7.00% debentures due 2018
Debt Instrument [Line Items]
Senior Notes	$ 0	62
Debt, interest rate	7.00%
Debt, maturity date	Dec. 31, 2018
7.375% notes due 2019
Debt Instrument [Line Items]
Senior Notes	$ 500	500
Debt, interest rate	7.375%
Debt, maturity date	Dec. 31, 2019
9.00% debentures due 2021
Debt Instrument [Line Items]
Senior Notes	$ 150	150
Debt, interest rate	9.00%
Debt, maturity date	Dec. 31, 2021
4.70% debentures due 2021
Debt Instrument [Line Items]
Senior Notes	$ 588	597
Debt, interest rate	4.70%
Debt, maturity date	Dec. 31, 2021
7.125% debentures due 2023
Debt Instrument [Line Items]
Senior Notes	$ 191	191
Debt, interest rate	7.125%
Debt, maturity date	Dec. 31, 2023
5.207% debentures due 2023
Debt Instrument [Line Items]
Senior Notes	$ 881	885
Debt, interest rate	5.207%
Debt, maturity date	Dec. 31, 2023
4.625% notes due 2023
Debt Instrument [Line Items]
Senior Notes	$ 500	500
Debt, interest rate	4.625%
Debt, maturity date	Dec. 31, 2023
3.25% debentures due 2023
Debt Instrument [Line Items]
Senior Notes	$ 324	324
Debt, interest rate	3.25%
Debt, maturity date	Dec. 31, 2023
8.50% debentures due 2025
Debt Instrument [Line Items]
Senior Notes	$ 300	300
Debt, interest rate	8.50%
Debt, maturity date	Dec. 31, 2025
7.95% debentures due 2025
Debt Instrument [Line Items]
Senior Notes	$ 136	136
Debt, interest rate	7.95%
Debt, maturity date	Dec. 31, 2025
7.70% debentures due 2026
Debt Instrument [Line Items]
Senior Notes	$ 150	150
Debt, interest rate	7.70%
Debt, maturity date	Dec. 31, 2026
7.35% debentures due 2026
Debt Instrument [Line Items]
Senior Notes	$ 62	62
Debt, interest rate	7.35%
Debt, maturity date	Dec. 31, 2026
7.85% debentures due 2026
Debt Instrument [Line Items]
Senior Notes	$ 100	100
Debt, interest rate	7.85%
Debt, maturity date	Dec. 31, 2026
Variable rate term loan credit facility matures 2026
Debt Instrument [Line Items]
Term loan credit facility	$ 225	225
Debt, interest rate	4.122%
Debt, maturity date	Dec. 31, 2026
6.95% debentures due 2027
Debt Instrument [Line Items]
Senior Notes	$ 300	300
Debt, interest rate	6.95%
Debt, maturity date	Dec. 31, 2027
7.375% debentures due 2032
Debt Instrument [Line Items]
Senior Notes	$ 1,250	1,250
Debt, interest rate	7.375%
Debt, maturity date	Dec. 31, 2032
6.875% debentures due 2033
Debt Instrument [Line Items]
Senior Notes	$ 275	$ 275
Debt, interest rate	6.875%
Debt, maturity date	Dec. 31, 2033

LONG-TERM DEBT - Amounts of Lon

LONG-TERM DEBT - Amounts of Long-Term Debt Due Annually for the Next Five Years and the Total Amount Due After 2022 (Details) $ in Millions	Dec. 31, 2018USD ($)
Long-term debt maturities
2,019	$ 500
2,020	0
2,021	719
2,022	0
2,023	1,876
Thereafter	$ 2,798

LONG-TERM DEBT - Additional Inf

LONG-TERM DEBT - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Line of Credit Facility, Expiration Date			Mar. 31, 2022
Long-term Debt, Gross			$ 5,933	$ 6,008
Proceeds from issuance of long-term debt			0	225	$ 1,698
Unamortized discounts, capitalized debt expense and fair value adjustments			26
7.00 percent debentures due 2018 [Member]
Debt Instrument [Line Items]
Senior Notes			$ 0	$ 62
Repayments of debt	$ 62
Interest rate, stated			7.00%
Debt, Maturity Date			Dec. 31, 2018
Variable rate term loan credit facility matures 2020
Debt Instrument [Line Items]
Line of Credit Facility, Expiration Date			Dec. 31, 2020
Repayments of debt		$ 550
Interest rate, stated			0.00%
Variable rate term loan credit facility matures 2026
Debt Instrument [Line Items]
Line of Credit Facility, Expiration Date			Dec. 31, 2026
Proceeds from issuance of long-term debt		225
Interest rate, stated			4.122%
Cash and Cash Equivalents | Variable rate term loan credit facility matures 2020
Debt Instrument [Line Items]
Repayments of debt		$ 325

FAIR VALUE OF FINANCIAL INSTR_3

FAIR VALUE OF FINANCIAL INSTRUMENTS - Estimated fair values and carrying values of our long-term debt and line of credit (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt (including current maturities) and line of credit, carrying value	$ 6,344	$ 5,992
Fair Value, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt (including current maturities) and line of credit, fair value	6,995	7,048
Fixed rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt (including current maturities) and line of credit, carrying value	5,694	5,768
Fixed rate | Fair Value, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt (including current maturities) and line of credit, fair value	6,345	6,823
Variable rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt (including current maturities) and line of credit, carrying value	650	224
Variable rate | Fair Value, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt (including current maturities) and line of credit, fair value	$ 650	$ 225

LEGAL PROCEEDINGS, COMMITMENT_3

LEGAL PROCEEDINGS, COMMITMENTS AND CONTINGENCIES - Changes in the Reserve for Environmental Remediation (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Environmental Exit Cost [Line Items]
Reserve balance as of December 31, 2017	$ 48
Reserve charges and adjustments, net	27
Payments	(13)
Reserve balance as of December 31, 2018	$ 62

LEGAL PROCEEDINGS, COMMITMENT_4

LEGAL PROCEEDINGS, COMMITMENTS AND CONTINGENCIES - Changes in the Reserve for Asset Retirement Obligations (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Loss Contingencies [Line Items]
Reserve balance as of December 31, 2017	$ 32
Reserve charges and adjustments, net	11
Payments	(12)
Other adjustments(1)	(2)
Reserve balance as of December 31, 2018	$ 29

LEGAL PROCEEDINGS, COMMITMENT_5

LEGAL PROCEEDINGS, COMMITMENTS AND CONTINGENCIES - Future Commitments on Operating Leases (Details) $ in Millions	Dec. 31, 2018USD ($)
Operating Leased Assets [Line Items]
Operating lease commitment due 2019	$ 35
Operating lease commitment due 2020	29
Operating lease commitment due 2021	26
Operating lease commitment due 2022	24
Operating lease commitment due 2023	18
Operating lease commitment due Thereafter	$ 78

LEGAL PROCEEDINGS, COMMITMENT_6

LEGAL PROCEEDINGS, COMMITMENTS AND CONTINGENCIES - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Remediation costs for all identified sites may exceed reserves	$ 126
Rent expense	47	$ 39	$ 37
Timberlands lease
Loss Contingencies [Line Items]
Guaranteed future payments on lease	$ 10

SHAREHOLDERS' INTEREST - Reconc

SHAREHOLDERS' INTEREST - Reconciliation of Our Common Share Activity (Details) - shares	Jul. 01, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Outstanding at beginning of year		755,222,727	748,528,000	510,483,000
Preference shares converted to common shares	23,200,000	0	0	23,345,000
Repurchased		(11,410,000)	0	(67,817,000)
Outstanding at end of year		746,390,932	755,222,727	748,528,000
Stock options
Class of Stock [Line Items]
Stock options exercised		2,026,000	5,970,000	2,571,000
Restricted stock units
Class of Stock [Line Items]
Stock options exercised		466,000	605,000	840,000
Performance share units
Class of Stock [Line Items]
Stock options exercised		86,000	120,000	219,000
Plum Creek
Class of Stock [Line Items]
Issuance from merger with Plum Creek (Note 5)		0	0	278,887,000

SHAREHOLDERS' INTEREST - Change

SHAREHOLDERS' INTEREST - Changes in amounts included in our cumulative other comprehensive income (loss) by component (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Beginning balance	$ (1,562)	$ (1,562)	$ (1,459)
Other comprehensive income (loss) before reclassifications (1)		347	(234)
Amounts reclassified from accumulated other comprehensive income (loss) to earnings(1)(2)		325	131
Total other comprehensive income (loss)		672	(103)
Reclassification of certain tax effects, due to tax law changes		(253)
Reclassification of accumulated unrealized gains on available-for-sale securities	(9)	(9)
Net amounts reclassified from accumulated other comprehensive income to retained earnings		(262)
Ending balance		(1,152)	(1,562)
Foreign currency translation adjustments
Beginning balance	264	264	232
Other comprehensive income (loss) before reclassifications (1)		(54)	32
Amounts reclassified from accumulated other comprehensive income (loss) to earnings(1)(2)		0	0
Total other comprehensive income (loss)		(54)	32
Reclassification of certain tax effects, due to tax law changes		0
Reclassification of accumulated unrealized gains on available-for-sale securities		0
Net amounts reclassified from accumulated other comprehensive income to retained earnings		0
Ending balance		210	264
Unrealized gains on available-for-sale securities
Beginning balance	9	9	7
Other comprehensive income (loss) before reclassifications (1)		0	2
Amounts reclassified from accumulated other comprehensive income (loss) to earnings(1)(2)		0	0
Total other comprehensive income (loss)		0	2
Reclassification of certain tax effects, due to tax law changes		0
Reclassification of accumulated unrealized gains on available-for-sale securities		(9)
Net amounts reclassified from accumulated other comprehensive income to retained earnings		(9)
Ending balance		0	9
Pension | Actuarial loss
Beginning balance	(1,802)	(1,802)	(1,651)
Other comprehensive income (loss) before reclassifications (1)		393	(280)
Amounts reclassified from accumulated other comprehensive income (loss) to earnings(1)(2)		322	129
Total other comprehensive income (loss)		715	(151)
Reclassification of certain tax effects, due to tax law changes		245
Reclassification of accumulated unrealized gains on available-for-sale securities		0
Net amounts reclassified from accumulated other comprehensive income to retained earnings		(245)
Ending balance		(1,332)	(1,802)
Pension | Prior service credits (costs)
Beginning balance	(8)	(8)	(9)
Other comprehensive income (loss) before reclassifications (1)		(5)	(2)
Amounts reclassified from accumulated other comprehensive income (loss) to earnings(1)(2)		3	3
Total other comprehensive income (loss)		(2)	1
Reclassification of certain tax effects, due to tax law changes		(1)
Reclassification of accumulated unrealized gains on available-for-sale securities		0
Net amounts reclassified from accumulated other comprehensive income to retained earnings		(1)
Ending balance		(11)	(8)
Other Postretirement Benefits | Actuarial loss
Beginning balance	(48)	(48)	(67)
Other comprehensive income (loss) before reclassifications (1)		12	14
Amounts reclassified from accumulated other comprehensive income (loss) to earnings(1)(2)		6	5
Total other comprehensive income (loss)		18	19
Reclassification of certain tax effects, due to tax law changes		(12)
Reclassification of accumulated unrealized gains on available-for-sale securities		0
Net amounts reclassified from accumulated other comprehensive income to retained earnings		(12)
Ending balance		(42)	(48)
Other Postretirement Benefits | Prior service credits (costs)
Beginning balance	$ 23	23	29
Other comprehensive income (loss) before reclassifications (1)		1	0
Amounts reclassified from accumulated other comprehensive income (loss) to earnings(1)(2)		(6)	(6)
Total other comprehensive income (loss)		(5)	(6)
Reclassification of certain tax effects, due to tax law changes		5
Reclassification of accumulated unrealized gains on available-for-sale securities		0
Net amounts reclassified from accumulated other comprehensive income to retained earnings		5
Ending balance		$ 23	$ 23

SHAREHOLDERS' INTEREST - Additi

SHAREHOLDERS' INTEREST - Additional Information (Details) $ / shares in Units, $ in Millions	Jul. 01, 2016shares	Jun. 24, 2013USD ($)$ / sharesshares	Jun. 28, 2016$ / shares	Dec. 31, 2018USD ($)$ / sharesshares	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015shares	Nov. 08, 2015USD ($)
Class of Stock [Line Items]
Preference shares conversion ratio	1.6929
Shares issued upon conversion of stock	23,200,000						0	0	23,345,000
Volume weighted average price per share | $ / shares			$ 29.54
Stock repurchase program, authorized repurchase amount | $											$ 2,500
Stock repurchase program, shares repurchased							11,410,000	0	67,817,000
Stock repurchase program, value repurchased | $							$ 0		$ 2,000
Stock repurchase program, remaining authorized repurchase amount | $				$ 135			$ 135	$ 500
Common shares, outstanding				746,390,932			746,390,932	755,222,727	748,528,000	510,483,000
Reclassification of certain tax effects, due to tax law changes | $							$ (253)
Reclassification of accumulated unrealized gains on available-for-sale securities | $					$ (9)		$ (9)
Unsettled share repurchases
Class of Stock [Line Items]
Stock repurchase program, shares repurchased							0	0
Preferred shares
Class of Stock [Line Items]
Preferred shares, outstanding				0			0	0
Preferred shares, authorized				7,000,000			7,000,000
Preferred shares, par value | $ / shares				$ 1			$ 1
6.375 percent Mandatory Convertible Preference Shares, Series A
Class of Stock [Line Items]
Preferred shares, outstanding	13,700,000
Preferred shares, par value | $ / shares		$ 1
New issuance		13,800,000
Preference shares, liquidation | $ / shares		$ 50
Net proceeds from issuance of preference shares | $		$ 669
Preferred Stock, Dividend Rate, Percentage	0.00%	0.00%
Pension
Class of Stock [Line Items]
Defined Benefit Plan, Plan Assets, Payment for Settlement | $				$ 200		$ 450		$ 0	$ 0

SHARE-BASED COMPENSATION - Sche

SHARE-BASED COMPENSATION - Schedule of Restricted Stock Units Activity (Details) - Restricted stock units - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock Units
Balance, beginning of year	1,515
Granted	710
Vested	(560)
Forfeited	(72)
Nonvested performance share units that have met the requisite service period and will be released as identified in the grant terms	336
Balance, end of year	1,593	1,515
Weighted Average Grant Date Fair Value
Balance, beginning of year	$ 29.12
Granted	34.19	$ 32.83	$ 30.25
Vested	28.81
Forfeited	30.19
Balance, end of year	$ 31.41	$ 29.12

SHARE-BASED COMPENSATION - Weig

SHARE-BASED COMPENSATION - Weighted Average Assumptions Used in Estimating the Value of Performance Share Units (Details) - Performance share units - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	1/1/2018-12/31/2020	1/1/2017 – 12/31/2019	1/1/2016 – 12/31/2018
Expected dividends	3.81%	3.74%
Risk-free rate minimum	1.75%	0.68%	0.45%
Risk-free rate maximum	2.34%	1.55%	0.97%
Volatility minimum	17.30%	22.71%	21.87%
Volatility maximum	21.52%	24.07%	28.09%
Weighted average grant-date fair value	$ 35.49	$ 37.93	$ 22.58
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends			3.92%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends			5.37%

SHARE-BASED COMPENSATION - Sc_2

SHARE-BASED COMPENSATION - Schedule of Performance Share Units Activity (Details) - Performance share units - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock Units
Balance, beginning of year	965
Granted	343
Vested	(112)
Forfeited	(26)
Balance, end of year	1,042	965
Nonvested performance share units that have met the requisite service period and will be released as identified in the grant terms	232
Weighted Average Grant Date Fair Value
Balance, beginning of year	$ 30.87
Granted	35.49	$ 37.93	$ 22.58
Vested	32.79
Forfeited	37.93
Balance, end of year	$ 31.52	$ 30.87
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance Adjustment	(128)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance Adjustment, Weighted Average Grant Date Fair Value	$ 34.74

SHARE-BASED COMPENSATION - Sc_3

SHARE-BASED COMPENSATION - Schedule of Stock Options Activity (Details) - Stock options $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)$ / sharesshares
Options
Balance, beginning of year	8,487
Exercised	(2,025)
Forfeited or expired	(96)
Balance, end of year	6,366
Exercisable, end of year	4,732
Number of options outstanding that have met the requisite service period and will be released as identifed in the grant terms	573
Weighted Average Exercise Price
Balance, beginning of year | $ / shares	$ 26.47
Exercised | $ / shares	25.68
Forfeited or expired | $ / shares	25.02
Balance, end of year | $ / shares	26.75
Exercisable, end of year | $ / shares	$ 27.14
Weighted Average Remaining Contractual Term
Balance, end of year	5 years 3 months 29 days
Exercisable, end of year	4 years 9 months 11 days
Aggregate Intrinsic Value
Balance, end of year | $	$ 4
Exercisable, end of year | $	$ 4

SHARE-BASED COMPENSATION - Addi

SHARE-BASED COMPENSATION - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Feb. 19, 2016
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options	$ 5	$ 6	$ 12
Share-based compensation expense	$ 42	$ 40	$ 60
Number of shares available for future grants under the Plan	20,554,887
IssuedSharesOfCommonStockPursuantToPerformanceIncentivePlanShares	30,000,000
Unrecognized share-based compensation cost for non-vested equity-classified share-based compensation arrangements	$ 33
Unrecognized share-based compensation costs for non-vested equity-classified share-based compensation arrangements, weighted average period for recognition	1 year 1 month 17 days
Number of common shares to be issued for directors who elected common share payments subsequent to year-end	639,000
Number of stock-equivalent units outstanding in deferred compensation accounts	788,444	803,850	1,004,448
Restricted stock, restricted stock units, performance shares, performance share units, or other equity grants [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares of shares an individual may receive in one year	1,000,000
Value of awards a participant may be granted in a 12 month period	$ 10
Stock options and stock appreciation rights [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares of shares an individual may receive in one year	2,000,000
Stock options
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total intrinsic value of stock options exercised	$ 22	$ 68	$ 18
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Restricted stock units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Weighted average grant-date fair value	$ 34.19	$ 32.83	$ 30.25
Total grant-date fair value vested	$ 16	$ 18	$ 36
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Performance share units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Weighted average grant-date fair value	$ 35.49	$ 37.93	$ 22.58
Total grant-date fair value vested	$ 4	$ 4	$ 8
Discontinued operations
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options			2
Share-based compensation expense			6
Plum Creek
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Acceleration of share-based compensation	$ 0	$ 0	$ 21
Plum Creek | Stock options
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of replacement equity awards issued				1,953,128
Value of replacement stock option awards issued				$ 5
Plum Creek | Restricted stock units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of replacement equity awards issued				1,248,006
Replacement RSUs with accelerated vesting		705,394
Acceleration of share-based compensation		$ 15
Plum Creek | Value management awards
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of replacement equity awards issued				289,910
Acceleration of share-based compensation		$ 6

CHARGES FOR INTEGRATION AND R_3

CHARGES FOR INTEGRATION AND RESTRUCTURING, CLOSURES AND ASSET IMPAIRMENTS - Items Included in Our Charges for Integration and Restructuring, Closures and Asset Impairments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Charges for integration and restructuring, closures and asset impairments
Impairment of long-lived assets	$ 1	$ 154	$ 16
Total charges for integration and restructuring, closures and asset impairments	2	194	170
Plum Creek
Charges for integration and restructuring, closures and asset impairments
Termination benefits	0	11	54
Acceleration of share-based compensation related to qualifying terminations (Note 17)	0	0	21
Acceleration of pension benefits related to qualifying terminations (Note 10)	0	0	5
Professional services	0	16	52
Other integration and restructuring costs	0	7	14
Total charges for integration and restructuring, closures and asset impairments	0	34	146
Other Closures and Restructuring
Charges for integration and restructuring, closures and asset impairments
Charges related to closures and other restructuring activities	$ 1	$ 6	$ 8

CHARGES FOR INTEGRATION AND R_4

CHARGES FOR INTEGRATION AND RESTRUCTURING, CLOSURES AND ASSET IMPAIRMENTS - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Asset Impairment Charges			$ 1	$ 154	$ 37
Proceeds, net of cash and cash equivalents disposed of			$ 0	$ 403	2,486
Timberlands
Asset Impairment Charges		$ 147
RE & ENR
Asset Impairment Charges					$ 15
Wood Products
Asset Impairment Charges	$ 6
Uruguayan Operations
Proceeds, net of cash and cash equivalents disposed of	$ 403

CHARGES (RECOVERIES) FOR PROD_2

CHARGES (RECOVERIES) FOR PRODUCT REMEDIATION, NET (Details) - Wood Products - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Product Liability Contingency [Line Items]
Insurance Recoveries	$ 25
Charges (recoveries) for product remediation, net	$ 25	$ 290

OTHER OPERATING COSTS (INCOME_3

OTHER OPERATING COSTS (INCOME), NET - Various Income and Expense Items Included in Other Operating Costs (Income), Net (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Gain on disposition of nonstrategic assets (1)	$ 36	$ (5)	$ (16)	$ (60)
Foreign exchange losses (gains), net (2)		(3)	(1)	(6)
Litigation expense, net		35	20	24
Gain on sale of timberlands (3)		0	(99)	0
Environmental remediation insurance recoveries		(5)	(42)	0
Other, net(4)		52	10	(11)
Total other operating costs (income), net		$ 74	$ (128)	$ (53)

INCOME TAXES - Domestic and For

INCOME TAXES - Domestic and Foreign Earnings from Continuing Operations Before Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Domestic earnings									$ 556	$ 643	$ 353
Foreign earnings									251	73	151
Earnings from continuing operations before income taxes	$ (114)	$ 240	$ 382	$ 299	$ 374	$ 103	$ 58	$ 181	$ 807	$ 716	$ 504

INCOME TAXES - Provision (Benef

INCOME TAXES - Provision (Benefit) for Income Taxes from Continuing Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ (69)	$ 10	$ 1
State	(5)	0	1
Foreign	61	82	11
Total	(13)	92	13
Deferred:
Federal	45	61	37
State	12	(18)	(3)
Foreign	15	(1)	42
Total	72	42	76
Total income tax provision (benefit)	$ 59	$ 134	$ 89

INCOME TAXES - Effective Income

INCOME TAXES - Effective Income Tax Rate Applicable to Continuing Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
U.S. federal statutory income tax	$ 170	$ 250	$ 177
State income taxes, net of federal tax benefit	8	(2)	(3)
REIT income not subject to federal income tax	(116)	(198)	(99)
SDT settlement	21	0	0
Tax affect of U.S. corporate rate change	0	74	0
Voluntary pension contribution	(41)	0	0
Foreign taxes	15	54	(4)
Repatriation of Canadian earnings	0	(22)	24
Other, net	2	(22)	(6)
Total income tax provision (benefit)	$ 59	$ 134	$ 89
Effective income tax rate	7.30%	18.80%	17.60%

INCOME TAXES - Balance Sheet Cl

INCOME TAXES - Balance Sheet Classification of Deferred Income Tax Assets (Liabilities) Related to Continuing Operations (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Net noncurrent deferred tax asset	$ 15	$ 268
Net noncurrent deferred tax liability	(43)	0
Net deferred tax asset (liability)	$ (28)	$ 268

INCOME TAXES - Items Included i

INCOME TAXES - Items Included in Our Deferred Income Tax Assets (Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Postretirement benefits	$ 37	$ 50
Pension	75	306
State tax credits	51	56
Other reserves	13	38
Depletion	41	40
Excess interest	30	0
Incentive compensation	20	23
Workers compensation	18	19
Net operating loss carryforwards	19	18
Other	83	70
Gross deferred tax assets	387	620
Valuation allowance	(61)	(63)
Net deferred tax assets	326	557
Property, plant and equipment	(197)	(154)
Timber installment notes	(116)	(116)
Other	(41)	(19)
Net deferred tax liabilities	(354)	(289)
Net deferred tax asset (liability)	$ (28)	$ 268

INCOME TAXES - Reconciliation o

INCOME TAXES - Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Balance at beginning of year	$ 4	$ 6
Lapse of statute	(1)	(2)
Balance at end of year	$ 3	$ 4

INCOME TAXES - Additional Infor

INCOME TAXES - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Federal Statutory Income Tax Rate, Percent		21.00%	35.00%
Valuation allowance		$ (61)	$ (63)
Unrecognized tax benefits		3	4	$ 6
Unrecognized tax benefits, net		1	2
Credits and loss carryovers		2	2
Unrecognized tax benefits that would affect our effective tax rate		1	2
Estimated decrease in unrecognized tax benefit due to the lapse of application statutes of limitation			1
Tax affect of U.S. corporate rate change		0	74	0
Tax provision benefit	$ 41
SDT settlement		21	0	$ 0
Foreign Tax Authority [Member]
Net operating loss carryforwards		0
Foreign undistributed earnings			$ 0
Federal, state and foreign
Net operating loss carryforwards		584
U.S. REIT
Net operating loss carryforwards		$ 223
Tax Credit Carryforward, Expiration Date		Dec. 31, 2027
Credit carryforwards		$ 6
U.S. REIT | Minimum
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2031
U.S. REIT | Maximum
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2036
State and Local Jurisdiction [Member]
Net operating loss carryforwards		$ 361
Credit carryforwards		$ 65
State and Local Jurisdiction [Member] | Minimum
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2019
Tax Credit Carryforward, Expiration Date		Dec. 31, 2019
State and Local Jurisdiction [Member] | Maximum
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2037
Tax Credit Carryforward, Expiration Date		Dec. 31, 2032
With expiration | State and Local Jurisdiction [Member]
Credit carryforwards		$ 14
Without expiration | State and Local Jurisdiction [Member]
Credit carryforwards		$ 51
Qualified Pension Plans, Defined Benefit [Member]
Payment for Pension Benefits	$ 300

GEOGRAPHIC AREAS - Sales by Geo

GEOGRAPHIC AREAS - Sales by Geographic Area (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 1,636	$ 1,910	$ 2,065	$ 1,865	$ 1,823	$ 1,872	$ 1,808	$ 1,693	$ 7,476	$ 7,196	$ 6,365
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									6,365	6,168	5,451
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									410	352	369
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									120	107	108
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									519	472	341
Other foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									62	97	96
Export sales from the U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									604	545	515
Export sales from the U.S. | Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									338	295	314
Export sales from the U.S. | China
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									113	102	103
Export sales from the U.S. | Other foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									$ 153	$ 148	$ 98

GEOGRAPHIC AREAS - Long-Lived A

GEOGRAPHIC AREAS - Long-Lived Assets by Geographic Area (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 14,998	$ 15,145	$ 16,433
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	14,778	14,922	15,700
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	220	223	206
Other foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 0	$ 0	$ 527

SELECTED QUARTERLY FINANCIAL _3

SELECTED QUARTERLY FINANCIAL INFORMATION (unaudited) - Key Quarterly Financial Data for the Last Two Years (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues	$ 1,636	$ 1,910	$ 2,065	$ 1,865	$ 1,823	$ 1,872	$ 1,808	$ 1,693	$ 7,476	$ 7,196	$ 6,365
Operating income from continuing operations	177	337	476	404	476	205	157	293	1,394	1,131	822
Earnings (loss) from continuing operations before income taxes	(114)	240	382	299	374	103	58	181	807	716	504
Net earnings	$ (93)	$ 255	$ 317	$ 269	$ 271	$ 130	$ 24	$ 157	$ 748	$ 582	$ 1,027
Basic and diluted net earnings (loss) per share	$ (0.12)	$ 0.34	$ 0.42	$ 0.35	$ 0.36	$ 0.17	$ 0.03	$ 0.21	$ 0.99	$ 0.77	$ 1.40
Dividends paid per share	$ 0.34	$ 0.34	$ 0.32	$ 0.32	$ 0.32	$ 0.31	$ 0.31	$ 0.31	$ 1.32	$ 1.25	$ 1.24
Continuing operations
Revenues											$ 6,365