Supplementary Financial Statement Information (Tables)
 12 Months Ended
Dec. 31, 2019
Disclosure Text Block Supplement [Abstract]  
Accounts And Notes Receivable [Table Text Block]
Accounts and notes receivable, net, by classification were: 
In millions at December 31
2019
2018
Accounts and notes receivable:
 
 
Trade
$
3,020

$
3,249

Other
260

272

Total
$
3,280

$
3,521
Inventories By Major Category [Table Text Block]
In millions at December 31
2019
2018
Raw materials
$
298

$
260

Finished pulp, paper and packaging products
1,192

1,241

Operating supplies
659

641

Other
59

99

Inventories
$
2,208

$
2,241
Plants, Properties And Equipment By Major Classification [Table Text Block]
In millions at December 31
2019
2018
Pulp, paper and packaging facilities
$
32,292

$
32,329

Other properties and equipment
1,224

1,232

Gross cost
33,516

33,561

Less: Accumulated depreciation
20,512

20,494

Plants, properties and equipment, net
$
13,004

$
13,067
Schedule of Other Income and Other Expense [Table Text Block]
Amounts related to interest were as follows: 
In millions
2019
2018
2017
Interest expense
$
706

$
734

$
758

Interest income
215

198

186

Capitalized interest costs
29

30

25