Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 26, 2021
Cover [Abstract]
Entity Registrant Name	WEYERHAEUSER COMPANY
Trading Symbol	WY
Entity Central Index Key	0000106535
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		749,215,000
Entity Shell Company	false
Entity File Number	1-4825
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	91-0470860
Entity Address, Address Line One	220 Occidental Avenue South
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98104-7800
City Area Code	(206)
Local Phone Number	539-3000
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $1.25 per share
Security Exchange Name	NYSE