BUSINESS SEGMENTS - Sales and Net Contribution (Charge) to Earnings (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers	$ 1,548	$ 1,671	$ 1,692	$ 1,643	$ 1,636	$ 1,910	$ 2,065	$ 1,865	$ 6,554	$ 7,476	$ 7,196
Net contribution (charge) to earnings									165	1,182	1,109
Timberlands
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									1,618	1,873	1,893
RE & ENR
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									313	306	280
Wood Products
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									4,623	5,297	5,023
Operating segments | Timberlands
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									1,618	1,873	1,893
Net contribution (charge) to earnings									347	583	532
Operating segments | RE & ENR
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									313	306	280
Net contribution (charge) to earnings									144	127	146
Operating segments | Wood Products
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									4,623	5,297	5,023
Net contribution (charge) to earnings									353	838	569
Unallocated Items
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									0	0	0
Net contribution (charge) to earnings									(679)	(366)	(138)
Intersegment eliminations
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									(504)	(538)	(523)
Intersegment eliminations | Timberlands
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									503	537	522
Intersegment eliminations | RE & ENR
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									1	1	1
Intersegment eliminations | Wood Products
Segment Reporting, Revenue Reconciling Item
Sales to unaffiliated customers									$ 0	$ 0	$ 0