REVENUE RECOGNITION Disaggregation of Revenue (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Net sales	[1]	$ 5,616	$ 4,866	$ 10,979	$ 10,218
Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	43	45	91	102
Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales		(35)	(30)	(64)	(63)
North American Industrial Packaging
Disaggregation of Revenue [Line Items]
Net sales		3,587	3,241	7,072	6,596
EMEA Industrial Packaging
Disaggregation of Revenue [Line Items]
Net sales		394	297	790	647
Brazilian Industrial Packaging
Disaggregation of Revenue [Line Items]
Net sales			42		96
European Coated Paperboard
Disaggregation of Revenue [Line Items]
Net sales		102	84	200	176
Global Cellulose Fibers
Disaggregation of Revenue [Line Items]
Net sales		671	605	1,252	1,173
North American Printing Papers
Disaggregation of Revenue [Line Items]
Net sales		410	265	776	711
Brazilian Papers
Disaggregation of Revenue [Line Items]
Net sales		189	108	357	284
European Papers
Disaggregation of Revenue [Line Items]
Net sales		255	209	505	496
United States
Disaggregation of Revenue [Line Items]
Net sales	[1]	4,379	3,906	8,529	8,032
United States | Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	42	44	89	102
EMEA
Disaggregation of Revenue [Line Items]
Net sales	[1]	835	652	1,656	1,448
EMEA | Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	(2)	(6)	(5)	(8)
Pacific Rim and Asia
Disaggregation of Revenue [Line Items]
Net sales	[1]	50	40	109	81
Pacific Rim and Asia | Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	3	7	7	10
Americas, other than U.S.
Disaggregation of Revenue [Line Items]
Net sales	[1]	352	268	685	657
Americas, other than U.S. | Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	0	0	0	(2)
Industrial Packaging
Disaggregation of Revenue [Line Items]
Net sales		4,056	3,633	8,009	7,452
Industrial Packaging | Geography Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales	[1]	4,056	3,633	8,009	7,452
Industrial Packaging | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Net sales		4,056	3,633	8,009	7,452
Industrial Packaging | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales		(27)	(31)	(53)	(63)
Industrial Packaging | North American Industrial Packaging
Disaggregation of Revenue [Line Items]
Net sales		3,587	3,241	7,072	6,596
Industrial Packaging | EMEA Industrial Packaging
Disaggregation of Revenue [Line Items]
Net sales		394	297	790	647
Industrial Packaging | Brazilian Industrial Packaging
Disaggregation of Revenue [Line Items]
Net sales			42		96
Industrial Packaging | European Coated Paperboard
Disaggregation of Revenue [Line Items]
Net sales		102	84	200	176
Industrial Packaging | United States
Disaggregation of Revenue [Line Items]
Net sales	[1]	3,354	3,065	6,611	6,195
Industrial Packaging | EMEA
Disaggregation of Revenue [Line Items]
Net sales	[1]	497	379	988	819
Industrial Packaging | Pacific Rim and Asia
Disaggregation of Revenue [Line Items]
Net sales	[1]	14	16	32	28
Industrial Packaging | Americas, other than U.S.
Disaggregation of Revenue [Line Items]
Net sales	[1]	191	173	378	410
Global Cellulose Fibers
Disaggregation of Revenue [Line Items]
Net sales		671	605	1,252	1,173
Global Cellulose Fibers | Geography Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales	[1]	671	605	1,252	1,173
Global Cellulose Fibers | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Net sales		671	605	1,252	1,173
Global Cellulose Fibers | Global Cellulose Fibers
Disaggregation of Revenue [Line Items]
Net sales		671	605	1,252	1,173
Global Cellulose Fibers | United States
Disaggregation of Revenue [Line Items]
Net sales	[1]	576	534	1,059	1,028
Global Cellulose Fibers | EMEA
Disaggregation of Revenue [Line Items]
Net sales	[1]	70	60	140	116
Global Cellulose Fibers | Pacific Rim and Asia
Disaggregation of Revenue [Line Items]
Net sales	[1]	25	11	53	29
Global Cellulose Fibers | Americas, other than U.S.
Disaggregation of Revenue [Line Items]
Net sales	[1]	0	0	0	0
Printing Papers
Disaggregation of Revenue [Line Items]
Net sales		846	583	1,627	1,491
Printing Papers | Geography Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales	[1]	846	583	1,627	1,491
Printing Papers | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Net sales		846	583	1,627	1,491
Printing Papers | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales		(8)	1	(11)	0
Printing Papers | North American Printing Papers
Disaggregation of Revenue [Line Items]
Net sales		410	265	776	711
Printing Papers | Brazilian Papers
Disaggregation of Revenue [Line Items]
Net sales		189	108	357	284
Printing Papers | European Papers
Disaggregation of Revenue [Line Items]
Net sales		255	209	505	496
Printing Papers | United States
Disaggregation of Revenue [Line Items]
Net sales	[1]	407	263	770	707
Printing Papers | EMEA
Disaggregation of Revenue [Line Items]
Net sales	[1]	270	219	533	521
Printing Papers | Pacific Rim and Asia
Disaggregation of Revenue [Line Items]
Net sales	[1]	8	6	17	14
Printing Papers | Americas, other than U.S.
Disaggregation of Revenue [Line Items]
Net sales	[1]	$ 161	$ 95	$ 307	$ 249

[1] Net sales are attributed to countries based on the location of the seller.