EARNINGS PER SHARE ATTRIBUTABLE TO INTERNATIONAL PAPER COMPANY COMMON SHAREHOLDERS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net Earnings (Loss) Attributable to International Paper Company	$ 864	$ 204	$ 1,645	$ 329
Weighted average common shares outstanding	388.8	393.1	391.0	392.9
Restricted performance share plan	3.8	1.5	4.3	1.6
Weighted average common shares outstanding – assuming dilution	392.6	394.6	395.3	394.5
Basic earnings (loss) per share attributable to International Paper Company Common Shareholders	$ 2.22	$ 0.52	$ 4.21	$ 0.84
Diluted earnings (loss) per share attributable to International Paper Company Common Shareholders	$ 2.20	$ 0.52	$ 4.16	$ 0.83