EQUITY (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Beginning Balance	$ 6,861,000,000	$ 7,469,000,000	$ 7,718,000,000	$ 7,383,000,000
Stockholders' Equity Attributable to Parent	7,057,000,000		7,057,000,000			$ 7,713,000,000
Retained earnings	8,123,000,000		8,123,000,000			8,408,000,000
Issuance of stock for various plans, net	4,000,000	35,000,000	45,000,000	80,000,000
Repurchase of stock		(231,000,000)	(41,000,000)	(460,000,000)
Common stock dividends	(205,000,000)	(201,000,000)	(408,000,000)	(408,000,000)
Transactions of equity method investees	29,000,000	36,000,000	35,000,000	33,000,000
Comprehensive income (loss)	371,000,000	391,000,000	(287,000,000)	871,000,000
Stockholders' equity attributable to noncontrolling interest	3,000,000		3,000,000			5,000,000
Ending Balance	7,060,000,000	7,499,000,000	7,060,000,000	7,499,000,000
Cumulative Effect Period of Adoption [Domain]
Retained earnings						(2,000,000)		$ 0
Common Stock Issued
Stockholders' Equity Attributable to Parent	449,000,000	449,000,000	449,000,000	449,000,000	$ 449,000,000	449,000,000	$ 449,000,000	449,000,000
Paid-in Capital
Stockholders' Equity Attributable to Parent	6,283,000,000	6,229,000,000	6,283,000,000	6,229,000,000	6,252,000,000	6,297,000,000	6,159,000,000	6,280,000,000
Issuance of stock for various plans, net	2,000,000	34,000,000	(49,000,000)	(84,000,000)
Transactions of equity method investees	29,000,000	36,000,000	35,000,000	33,000,000
Retained Earnings
Stockholders' Equity Attributable to Parent	8,123,000,000	8,302,000,000	8,123,000,000	8,302,000,000	8,062,000,000	8,408,000,000	8,211,000,000	7,465,000,000
Common stock dividends	(205,000,000)	(201,000,000)	(408,000,000)	(408,000,000)
Comprehensive income (loss)	266,000,000	292,000,000	125,000,000	716,000,000
Retained Earnings | Cumulative Effect Period of Adoption [Domain]
Retained earnings						(2,000,000)		(529,000,000)
Accumulated Other Comprehensive Income (Loss)
Stockholders' Equity Attributable to Parent	(5,149,000,000)	(4,870,000,000)	(5,149,000,000)	(4,870,000,000)	(5,255,000,000)	(4,739,000,000)	(4,975,000,000)	(4,500,000,000)
Comprehensive income (loss)	106,000,000	105,000,000	(410,000,000)	159,000,000
Accumulated Other Comprehensive Income (Loss) | Cumulative Effect Period of Adoption [Domain]
Retained earnings								529,000,000
Common Stock Held In Treasury, At Cost
Stockholders' Equity Attributable to Parent	2,649,000,000	2,628,000,000	2,649,000,000	2,628,000,000	2,651,000,000	2,702,000,000	2,398,000,000	2,332,000,000
Issuance of stock for various plans, net	(2,000,000)	(1,000,000)	(94,000,000)	(164,000,000)
Repurchase of stock		231,000,000	41,000,000	460,000,000
Total International Paper Shareholders’ Equity
Stockholders' Equity Attributable to Parent	7,057,000,000	7,482,000,000	7,057,000,000	7,482,000,000	6,857,000,000	7,713,000,000	7,446,000,000	7,362,000,000
Issuance of stock for various plans, net	4,000,000	35,000,000	45,000,000	80,000,000
Repurchase of stock		(231,000,000)	(41,000,000)	(460,000,000)
Common stock dividends	(205,000,000)	(201,000,000)	(408,000,000)	(408,000,000)
Transactions of equity method investees	29,000,000	36,000,000	35,000,000	33,000,000
Comprehensive income (loss)	372,000,000	397,000,000	(285,000,000)	875,000,000
Total International Paper Shareholders’ Equity | Cumulative Effect Period of Adoption [Domain]
Retained earnings						(2,000,000)
Noncontrolling Interests
Comprehensive income (loss), portion attributable to noncontrolling interest	(1,000,000)	(6,000,000)	(2,000,000)	(4,000,000)
Stockholders' equity attributable to noncontrolling interest	$ 3,000,000	$ 17,000,000	$ 3,000,000	$ 17,000,000	$ 4,000,000	$ 5,000,000	$ 23,000,000	$ 21,000,000