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