REVENUE RECOGNITION Disaggregation of Revenue (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
Disaggregation of Revenue [Line Items]
Net sales	[1],[2]	$ 5,901	$ 4,619
Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Net sales		5,895	4,538
Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales		6	81
United States
Disaggregation of Revenue [Line Items]
Net sales	[1]	4,123	3,996
United States | Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	6	81
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Net sales	[1]	1,573	368
Europe, Middle East and Africa | Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	0	0
Pacific Rim and Asia
Disaggregation of Revenue [Line Items]
Net sales	[1]	12	48
Pacific Rim and Asia | Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	0	0
Americas, other than U.S.
Disaggregation of Revenue [Line Items]
Net sales	[1]	193	207
Americas, other than U.S. | Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	0	0
Packaging Solutions North America | Geography Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales	[1]	3,702	3,486
Packaging Solutions North America | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Net sales		3,702	3,486
Packaging Solutions North America | United States
Disaggregation of Revenue [Line Items]
Net sales	[1]	3,498	3,265
Packaging Solutions North America | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Net sales	[1]	0	0
Packaging Solutions North America | Pacific Rim and Asia
Disaggregation of Revenue [Line Items]
Net sales	[1]	11	14
Packaging Solutions North America | Americas, other than U.S.
Disaggregation of Revenue [Line Items]
Net sales	[1]	193	207
Global Cellulose Fibers | Geography Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales	[1]	643	704
Global Cellulose Fibers | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Net sales		643	704
Global Cellulose Fibers | United States
Disaggregation of Revenue [Line Items]
Net sales	[1]	619	650
Global Cellulose Fibers | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Net sales	[1]	23	20
Global Cellulose Fibers | Pacific Rim and Asia
Disaggregation of Revenue [Line Items]
Net sales	[1]	1	34
Global Cellulose Fibers | Americas, other than U.S.
Disaggregation of Revenue [Line Items]
Net sales	[1]	0	0
Corporate Segment and Other Operating Segment [Member] | Consolidation, Eliminations
Disaggregation of Revenue [Line Items]
Net sales	[1]	6	81
Packaging Solutions EMEA | Geography Eliminations [Member]
Disaggregation of Revenue [Line Items]
Net sales	[1]	1,550	348
Packaging Solutions EMEA | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Net sales		1,550	348
Packaging Solutions EMEA | United States
Disaggregation of Revenue [Line Items]
Net sales	[1]	0	0
Packaging Solutions EMEA | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Net sales	[1]	1,550	348
Packaging Solutions EMEA | Pacific Rim and Asia
Disaggregation of Revenue [Line Items]
Net sales	[1]	0	0
Packaging Solutions EMEA | Americas, other than U.S.
Disaggregation of Revenue [Line Items]
Net sales	[1]	$ 0	$ 0

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

[2] External sales by segment are defined as those made to parties outside International Paper’s consolidated group, whereas sales by segment in the Net Sales table are determined using a management approach and include intersegment sales.