(Reconciliation Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings (loss) from continuing operations attributable to International Paper common shareholders	$ 482	$ 1,225	$ 1,667
Weighted average common shares outstanding	393.0	395.3	409.1
Effect of dilutive securities:	2.7	3.5	5.1
Weighted average common shares outstanding  – assuming dilution	395.7	398.8	414.2
Basic earnings (loss) per share from continuing operations	$ 1.23	$ 3.10	$ 4.07
Diluted earnings (loss) per share from continuing operations	$ 1.22	$ 3.07	$ 4.02