CONDENSED CONSOLIDATING FINANCIAL INFORMATION Condensed Consolidating Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Net sales	$ 1,655	$ 1,345	$ 3,060	$ 2,625
Costs of products sold	1,258	1,057	2,347	2,050
Gross margin	397	288	713	575
Other operating expenses, net	139	88	302	225
Operating income	258	200	411	350
Non-operating expense, net	(97)	(76)	(178)	(149)
Earnings from continuing operations before income taxes	161	124	233	201
Income taxes	(31)	1	(42)	(8)
Earnings from continuing operations	130	125	191	193
Earnings from discontinued operations, net of income taxes (Note 3)	38	19	58	52
Net earnings	168	144	249	245
Dividends on preference shares	(11)	(11)	(22)	(22)
Net earnings attributable to Weyerhaeuser common shareholders	157	133	227	223
Foreign currency translation adjustments	(2)	12	39	(35)
Actuarial gains, net of tax expense	31	44	41	106
Prior service costs, net of tax expense	0	0	(2)	(2)
Unrealized gains on available-for-sale securities	1	0	1	1
Total other comprehensive income	30	56	79	70
Comprehensive income (loss)	198	200	328	315
Cash and cash equivalents	485	1,117	485	1,117	$ 1,011	$ 1,577
Other current assets	935		935		694
Assets of discontinued operations (Note 3)	1,908		1,908		1,934
Total current assets	3,328		3,328		3,639
Property and equipment, net	1,462		1,462		1,233
Timber and timberlands at cost, net	14,474		14,474		6,479
Investments in and advances to subsidiaries	0		0		0
Other assets	2,725		2,725		1,369
Total assets	21,989		21,989		12,720
Current liabilities	891		891		635
Liabilities of discontinued operations (Note 3)	666		666		690
Total current liabilities	1,557		1,557		1,325
Note payable to Timberland Venture	830		830		0
Long-term debt	8,013		8,013		4,787
Other long-term liabilities	2,159		2,159		1,739
Total liabilities	12,559		12,559		7,851
Mandatory convertible preference shares	14		14		14
Common shares	916		916		638
Other equity	8,500		8,500		4,217
Total equity	9,430		9,430		4,869
Total liabilities and equity	21,989		21,989		12,720
Net cash from (used in) operations			539	454
Capital expenditures			(174)	(197)
Acquisition of timberlands			(8)	(32)
Proceeds from sale of non-strategic assets			83	6
Proceeds from contribution of timberlands to related party (Note 7)			440	0
Distributions received from joint ventures			27	0
Cash acquired in merger with Plum Creek			9	0
Issuance of note to parent				0
Distribution from subsidiaries			0	0
Other			(3)	12
Net cash from (used in) investing activities			374	(211)
Net proceeds from issuance of debt			1,398	0
Payments on debt			(723)	0
Proceeds from note from subsidiary				0
Cash dividends on common shares			(469)	(301)
Cash dividends on preference shares			(11)	(11)
Repurchase of common stock			(1,629)	(407)
Distribution to parent			0	0
Other			1	17
Net cash from (used in) financing activities			(1,433)	(702)
Subsidiary Issuer [Member]
Guaranteed registered debt securities	894		894
Reportable Legal Entities [Member] | Parent Company [Member]
Net sales	186	181	372	379
Costs of products sold	68	55	125	116
Gross margin	118	126	247	263
Other operating expenses, net	12	17	93	36
Operating income	106	109	154	227
Non-operating expense, net	(23)	(13)	(35)	(19)
Earnings from continuing operations before income taxes	83	96	119	208
Income taxes	0	0	0	0
Earnings from continuing operations	83	96	119	208
Earnings from discontinued operations, net of income taxes (Note 3)	0	0	0	0
Net earnings	83	96	119	208
Dividends on preference shares	(11)	(11)	(22)	(22)
Net earnings attributable to Weyerhaeuser common shareholders	72	85	97	186
Foreign currency translation adjustments	0	0	0	0
Actuarial gains, net of tax expense	1	(1)	3	4
Prior service costs, net of tax expense	0	(1)	0	(1)
Unrealized gains on available-for-sale securities	0	0	0	0
Total other comprehensive income	1	(2)	3	3
Comprehensive income (loss)	84	94	122	211
Cash and cash equivalents	69		69		673
Other current assets	73		73		7
Assets of discontinued operations (Note 3)	0		0		0
Total current assets	142		142		680
Property and equipment, net	165		165		167
Timber and timberlands at cost, net	3,454		3,454		3,538
Investments in and advances to subsidiaries	11,875		11,875		2,948
Other assets	96		96		88
Total assets	15,732		15,732		7,421
Current liabilities	174		174		66
Liabilities of discontinued operations (Note 3)	0		0		0
Total current liabilities	174		174		66
Note payable to Timberland Venture	0		0
Long-term debt	3,935		3,935		1,645
Other long-term liabilities	87		87		91
Total liabilities	4,196		4,196		1,802
Mandatory convertible preference shares	14		14		14
Common shares	916		916		638
Other equity	10,606		10,606		4,967
Total equity	11,536		11,536		5,619
Total liabilities and equity	15,732		15,732		7,421
Net cash from (used in) operations			40	(4)
Capital expenditures			(25)	(30)
Acquisition of timberlands			(1)	(26)
Proceeds from sale of non-strategic assets			0	0
Proceeds from contribution of timberlands to related party (Note 7)			0
Distributions received from joint ventures			0
Cash acquired in merger with Plum Creek			0
Issuance of note to parent				0
Distribution from subsidiaries			812	292
Other			0	12
Net cash from (used in) investing activities			786	248
Net proceeds from issuance of debt			1,398
Payments on debt			(720)
Proceeds from note from subsidiary				600
Cash dividends on common shares			(469)	(301)
Cash dividends on preference shares			(11)	(11)
Repurchase of common stock			(1,629)	(407)
Distribution to parent			0	0
Other			1	17
Net cash from (used in) financing activities			(1,430)	(102)
Reportable Legal Entities [Member] | Subsidiary Issuer [Member]
Net sales	55	0	82	0
Costs of products sold	37	0	61	0
Gross margin	18	0	21	0
Other operating expenses, net	14	0	36	0
Operating income	4	0	(15)	0
Non-operating expense, net	(9)	0	(15)	0
Earnings from continuing operations before income taxes	(5)	0	(30)	0
Income taxes	0	0	0	0
Earnings from continuing operations	(5)	0	(30)	0
Earnings from discontinued operations, net of income taxes (Note 3)	0	0	0	0
Net earnings	(5)	0	(30)	0
Dividends on preference shares	0	0	0	0
Net earnings attributable to Weyerhaeuser common shareholders	(5)	0	(30)	0
Foreign currency translation adjustments	0	0	0	0
Actuarial gains, net of tax expense	0	0	0	0
Prior service costs, net of tax expense	0	0	0	0
Unrealized gains on available-for-sale securities	1	0	1	0
Total other comprehensive income	1	0	1	0
Comprehensive income (loss)	(4)	0	(29)	0
Cash and cash equivalents	20		20		0
Other current assets	7		7		0
Assets of discontinued operations (Note 3)	0		0		0
Total current assets	27		27		0
Property and equipment, net	89		89		0
Timber and timberlands at cost, net	5,813		5,813		0
Investments in and advances to subsidiaries	4,565		4,565		0
Other assets	139		139		0
Total assets	10,633		10,633		0
Current liabilities	83		83		0
Liabilities of discontinued operations (Note 3)	0		0		0
Total current liabilities	83		83		0
Note payable to Timberland Venture	0		0
Long-term debt	935		935		0
Other long-term liabilities	498		498		0
Total liabilities	1,516		1,516		0
Mandatory convertible preference shares	0		0		0
Common shares	0		0		0
Other equity	9,117		9,117		0
Total equity	9,117		9,117		0
Total liabilities and equity	10,633		10,633		0
Net cash from (used in) operations			38	0
Capital expenditures			(9)	0
Acquisition of timberlands			0	0
Proceeds from sale of non-strategic assets			0	0
Proceeds from contribution of timberlands to related party (Note 7)			440
Distributions received from joint ventures			0
Cash acquired in merger with Plum Creek			5
Issuance of note to parent				0
Distribution from subsidiaries			0	0
Other			(3)	0
Net cash from (used in) investing activities			433	0
Net proceeds from issuance of debt			0
Payments on debt			0
Proceeds from note from subsidiary				0
Cash dividends on common shares			0	0
Cash dividends on preference shares			0	0
Repurchase of common stock			0	0
Distribution to parent			(451)	0
Other			0	0
Net cash from (used in) financing activities			(451)	0
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Net sales	1,618	1,327	2,996	2,579
Costs of products sold	1,360	1,170	2,551	2,273
Gross margin	258	157	445	306
Other operating expenses, net	113	71	173	189
Operating income	145	86	272	117
Non-operating expense, net	(65)	(63)	(128)	(130)
Earnings from continuing operations before income taxes	80	23	144	(13)
Income taxes	(31)	1	(42)	(8)
Earnings from continuing operations	49	24	102	(21)
Earnings from discontinued operations, net of income taxes (Note 3)	38	19	58	52
Net earnings	87	43	160	31
Dividends on preference shares	0	0	0	0
Net earnings attributable to Weyerhaeuser common shareholders	87	43	160	31
Foreign currency translation adjustments	(2)	12	39	(35)
Actuarial gains, net of tax expense	30	45	38	102
Prior service costs, net of tax expense	0	1	(2)	(1)
Unrealized gains on available-for-sale securities	0	0	0	1
Total other comprehensive income	28	58	75	67
Comprehensive income (loss)	115	101	235	98
Cash and cash equivalents	396		396		338
Other current assets	863		863		693
Assets of discontinued operations (Note 3)	1,908		1,908		1,934
Total current assets	3,167		3,167		2,965
Property and equipment, net	1,208		1,208		1,066
Timber and timberlands at cost, net	5,228		5,228		2,964
Investments in and advances to subsidiaries	630		630		0
Other assets	3,125		3,125		1,916
Total assets	13,358		13,358		8,911
Current liabilities	639		639		574
Liabilities of discontinued operations (Note 3)	666		666		690
Total current liabilities	1,305		1,305		1,264
Note payable to Timberland Venture	830		830
Long-term debt	3,743		3,743		3,742
Other long-term liabilities	1,574		1,574		1,648
Total liabilities	7,452		7,452		6,654
Mandatory convertible preference shares	0		0		0
Common shares	0		0		0
Other equity	5,906		5,906		2,257
Total equity	5,906		5,906		2,257
Total liabilities and equity	13,358		13,358		8,911
Net cash from (used in) operations			461	458
Capital expenditures			(140)	(167)
Acquisition of timberlands			(7)	(6)
Proceeds from sale of non-strategic assets			83	6
Proceeds from contribution of timberlands to related party (Note 7)			0
Distributions received from joint ventures			27
Cash acquired in merger with Plum Creek			4
Issuance of note to parent				(600)
Distribution from subsidiaries			0	0
Other			0	0
Net cash from (used in) investing activities			(33)	(767)
Net proceeds from issuance of debt			0
Payments on debt			(3)
Proceeds from note from subsidiary				0
Cash dividends on common shares			0	0
Cash dividends on preference shares			0	0
Repurchase of common stock			0	0
Distribution to parent			(361)	(292)
Other			0	0
Net cash from (used in) financing activities			(364)	(292)
Consolidation, Eliminations [Member]
Net sales	(204)	(163)	(390)	(333)
Costs of products sold	(207)	(168)	(390)	(339)
Gross margin	3	5	0	6
Other operating expenses, net	0	0	0	0
Operating income	3	5	0	6
Non-operating expense, net	0	0	0	0
Earnings from continuing operations before income taxes	3	5	0	6
Income taxes	0	0	0	0
Earnings from continuing operations	3	5	0	6
Earnings from discontinued operations, net of income taxes (Note 3)	0	0	0	0
Net earnings	3	5	0	6
Dividends on preference shares	0	0	0	0
Net earnings attributable to Weyerhaeuser common shareholders	3	5	0	6
Foreign currency translation adjustments	0	0	0	0
Actuarial gains, net of tax expense	0	0	0	0
Prior service costs, net of tax expense	0	0	0	0
Unrealized gains on available-for-sale securities	0	0	0	0
Total other comprehensive income	0	0	0	0
Comprehensive income (loss)	3	$ 5	0	6
Cash and cash equivalents	0		0		0
Other current assets	(8)		(8)		(6)
Assets of discontinued operations (Note 3)	0		0		0
Total current assets	(8)		(8)		(6)
Property and equipment, net	0		0		0
Timber and timberlands at cost, net	(21)		(21)		(23)
Investments in and advances to subsidiaries	(17,070)		(17,070)		(2,948)
Other assets	(635)		(635)		(635)
Total assets	(17,734)		(17,734)		(3,612)
Current liabilities	(5)		(5)		(5)
Liabilities of discontinued operations (Note 3)	0		0		0
Total current liabilities	(5)		(5)		(5)
Note payable to Timberland Venture	0		0
Long-term debt	(600)		(600)		(600)
Other long-term liabilities	0		0		0
Total liabilities	(605)		(605)		(605)
Mandatory convertible preference shares	0		0		0
Common shares	0		0		0
Other equity	(17,129)		(17,129)		(3,007)
Total equity	(17,129)		(17,129)		(3,007)
Total liabilities and equity	$ (17,734)		(17,734)		$ (3,612)
Net cash from (used in) operations			0	0
Capital expenditures			0	0
Acquisition of timberlands			0	0
Proceeds from sale of non-strategic assets			0	0
Proceeds from contribution of timberlands to related party (Note 7)			0
Distributions received from joint ventures			0
Cash acquired in merger with Plum Creek			0
Issuance of note to parent				600
Distribution from subsidiaries			(812)	(292)
Other			0	0
Net cash from (used in) investing activities			(812)	308
Net proceeds from issuance of debt			0
Payments on debt			0
Proceeds from note from subsidiary				(600)
Cash dividends on common shares			0	0
Cash dividends on preference shares			0	0
Repurchase of common stock			0	0
Distribution to parent			812	292
Other			0	0
Net cash from (used in) financing activities			$ 812	$ (308)