Related Party Transactions (Details) - NACP Combination - International Paper Company - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Fiber Procurement And Corrugated Products
Related Party Transaction [Line Items]
Payments to suppliers	$ 9.2	$ 8.6
Wood
Related Party Transaction [Line Items]
Payments to suppliers	154.0	178.0
Transition Services
Related Party Transaction [Line Items]
Payments to suppliers		0.1
Ink Supply
Related Party Transaction [Line Items]
Payments to suppliers	$ 21.7	19.7
Unrelated To Agreements
Related Party Transaction [Line Items]
Payments to suppliers		$ 3.0

Payments of cash to suppliers for goods and services during the current period.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3367-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3367-108585

Name:	us-gaap_PaymentsToSuppliers
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration