(Business Special Items By Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Business net special items	$ 490	$ 307	$ 205
Industrial Packaging | Operating Segments [Member]
Segment Reporting Information [Line Items]
Business net special items	475	78	184
Global Cellulose Fibers | Operating Segments [Member]
Segment Reporting Information [Line Items]
Business net special items	5	68	11
Printing Papers | Operating Segments [Member]
Segment Reporting Information [Line Items]
Business net special items	$ 10	$ 161	$ 10