EARNINGS PER SHARE ATTRIBUTABLE TO INTERNATIONAL PAPER COMPANY COMMON SHAREHOLDERS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Earnings (Loss) Attributable to International Paper Company		$ 432	$ 266	$ 781	$ 125
Weighted average common shares outstanding		391.5	393.1	392.1	392.9
Restricted performance share plan	[1]	5.3	0.0	5.6	1.1
Weighted average common shares outstanding – assuming dilution		396.8	393.1	397.7	394.0
Basic earnings (loss) per share attributable to International Paper Company Common Shareholders		$ 1.10	$ 0.67	$ 1.99	$ 0.32
Diluted earnings (loss) per share attributable to International Paper Company Common Shareholders		$ 1.09	$ 0.67	$ 1.96	$ 0.32

[1] Securities are not included in the table in periods when antidilutive