General Information - Narrative (Details) shares in Millions			3 Months Ended						6 Months Ended	24 Months Ended
	Apr. 01, 2020 facility	Jan. 29, 2020 USD ($) shares	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	[1]	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	[2]	Jun. 30, 2020 USD ($)	Dec. 31, 2019 shares	Jan. 28, 2020	Jan. 01, 2018
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Shares repurchased (in shares) | shares		15.1								20.8
Cash paid for repurchase of common stock		$ 250,000,000	$ 33,100,000	$ 124,400,000		$ 18,300,000	$ 59,500,000
Number of converting facilities | facility	7
International Paper Company
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of days after exchange									180 days
Dollar limit per unit exchange (lesser of)									$ 250,000,000
Percentage limit per unit exchange (lesser of)									25.00%
International Paper Company
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
IP's ownership interest in GPIP		18.30%								21.60%	21.60%	20.50%

[1] Includes 410,400 shares repurchased but not yet settled as of March 31, 2020.^(b) Includes 14,436 shares repurchased but not yet settled as of June 30, 2020.

[2] Includes 33,263 shares repurchased but not yet settled as of March 31, 2019.