CHARGES FOR INTEGRATION AND RESTRUCTURING, CLOSURES AND ASSET IMPAIRMENTS - Additional Information (Details) $ in Millions		3 Months Ended	12 Months Ended
	Dec. 17, 2019 a	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Restructuring Cost And Reserve [Line Items]
Impairment charges		$ 80	$ 80
Asset Impairment Charges			80	$ 1	$ 154
Montana
Restructuring Cost And Reserve [Line Items]
Impairment charges			80
Number of acers of timberlands agreed to be sold | a	630,000
Cash purchase price of assets to be disposed of			145
Timberlands
Restructuring Cost And Reserve [Line Items]
Impairment charges			$ 80
Asset Impairment Charges					147
Plum Creek
Restructuring Cost And Reserve [Line Items]
Total charges for termination benefits					34
Other Closures and Restructuring
Restructuring Cost And Reserve [Line Items]
Total charges for other restructuring and closure costs					$ 6