REVENUE RECOGNITION - Revenue by Major Products (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue from External Customer
Net sales	$ 7,532	$ 6,554	$ 7,476
Timberlands
Revenue from External Customer
Net sales	1,466	1,618	1,873
Timberlands | Delivered logs
Revenue from External Customer
Net sales	1,345	1,472	1,711
Timberlands | Stumpage and pay-as-cut timber
Revenue from External Customer
Net sales	19	42	59
Timberlands | Recreational and other lease revenue
Revenue from External Customer
Net sales	63	61	59
Timberlands | Other
Revenue from External Customer
Net sales	39	43	44
Timberlands | West | Delivered logs
Revenue from External Customer
Net sales	720	740	987
Timberlands | South | Delivered logs
Revenue from External Customer
Net sales	573	640	625
Timberlands | North | Delivered logs
Revenue from External Customer
Net sales	52	92	99
Timberlands | Domestic grade sales | West | Delivered logs
Revenue from External Customer
Net sales	329	375	503
Timberlands | Export grade sales | West | Delivered logs
Revenue from External Customer
Net sales	391	365	484
Real Estate & ENR
Revenue from External Customer
Net sales	276	313	306
Real Estate & ENR | Real Estate
Revenue from External Customer
Net sales	202	225	229
Real Estate & ENR | Energy and natural resources
Revenue from External Customer
Net sales	74	88	77
Wood Products
Revenue from External Customer
Net sales	5,790	4,623	5,297
Wood Products | Structural lumber
Revenue from External Customer
Net sales	2,602	1,892	2,258
Wood Products | Oriented strand board
Revenue from External Customer
Net sales	1,013	632	891
Wood Products | Engineered solid section
Revenue from External Customer
Net sales	505	510	521
Wood Products | Engineered I-joists
Revenue from External Customer
Net sales	316	323	336
Wood Products | Softwood plywood
Revenue from External Customer
Net sales	171	161	200
Wood Products | Medium density fiberboard
Revenue from External Customer
Net sales	171	166	177
Wood Products | Complementary building products
Revenue from External Customer
Net sales	676	602	584
Wood Products | Other
Revenue from External Customer
Net sales	$ 336	$ 337	$ 330