BUSINESS SEGMENTS - Reconciliation from Segment Totals to Consolidated (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 1,820	$ 1,915	$ 5,348	$ 5,615
Net contribution to earnings	263	1,297	711	2,070
Interest expense, net of capitalized interest (continuing and discontinued operations)	(88)	(89)	(259)	(257)
Income before income taxes (continuing and discontinued operations)	175	1,208	452	1,813
Income taxes (continuing and discontinued operations)	16	(44)	(16)	(164)
Net earnings	191	1,164	436	1,649
Dividends on preference shares	(11)	(11)	(33)	(33)
Net earnings attributable to Weyerhaeuser common shareholders	180	1,153	403	1,616
Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,820	1,915	5,348	5,615
Discontinued operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net contribution to earnings	0	972	0	1,017
Operating segments \| Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	2,050	2,153	6,034	6,317
Net contribution to earnings	290	300	772	945
Operating segments \| Timberlands \| Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	326	364	1,013	1,138
Net contribution to earnings	126	136	415	470
Operating segments \| Wood Products \| Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,023	1,048	2,950	3,023
Net contribution to earnings	85	105	218	271
Operating segments \| Cellulose Fibers \| Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	471	503	1,385	1,454
Net contribution to earnings	79	59	139	204
Operating intersegments \| Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	230	238	686	702
Operating intersegments \| Timberlands \| Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	210	218	625	642
Operating intersegments \| Wood Products \| Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	20	20	61	60
Intersegment eliminations \| Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	(230)	(238)	(686)	(702)
Unallocated Items \| Continuing operations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net contribution to earnings	$ (27)	$ 25	$ (61)	$ 108

Amount of current tax expense (benefit) and deferred tax expense (benefit) from income (loss) from continuing operations, income (loss) from discontinued operations, and gain (loss) from extraordinary items.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 20

-Section 45

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=18498875&loc=d3e38976-109324

+ Details

Name:	us-gaap_IncomeTaxExpenseBenefitContinuingOperationsDiscontinuedOperationsExtraordinaryItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Net Income

-URI http://asc.fasb.org/extlink&oid=51831255

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.19)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.18)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.22)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Other Comprehensive Income

-URI http://asc.fasb.org/extlink&oid=51831270

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 19

-Article 5

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 20

-Article 9

+ Details

Name:	us-gaap_NetIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1377-109256

+ Details

Name:	us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of preferred stock dividends that is an adjustment to net income apportioned to common stockholders.

+ References

No definition available.

+ Details

Name:	us-gaap_PreferredStockDividendsIncomeStatementImpact
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

Name:	us-gaap_SalesRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_SegmentReportingRevenueReconcilingItemLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the income or loss from both continuing operations and discontinued operations to the economic entity, after income or loss from equity method investments, but before income taxes, extraordinary items.

+ References

No definition available.

+ Details

Name:	wy_IncomeLossBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Namespace Prefix:	wy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of the cost of borrowed funds accounted for as interest expense, including continuing and discontinued operations.

+ References

No definition available.

+ Details

Name:	wy_InterestExpenseIncludingContinuingandDiscontinuedOperations
Namespace Prefix:	wy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents the income or (loss) from continuing operations (before interest expense) attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before, interest expense, income taxes, extraordinary items, and noncontrolling interest.

+ References

No definition available.

+ Details

Name:	wy_NetContributionToEarnings
Namespace Prefix:	wy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_StatementOperatingActivitiesSegmentAxis=us-gaap_SegmentContinuingOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementOperatingActivitiesSegmentAxis=us-gaap_SegmentDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=wy_TimberlandsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=wy_WoodProductsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=wy_CelluloseFibersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidationItemsAxis=wy_OperatingIntersegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_CorporateNonSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: