Supplementary Financial Statement Information (Plants, Properties And Equipment By Major Classification) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Gross cost	$ 33,814	$ 32,251
Less: Accumulated depreciation	20,549	19,248
Plants, properties and equipment, net	13,265	13,003
Pulp, paper and packaging facilities
Property, Plant and Equipment [Line Items]
Gross cost	32,523	30,943
Other properties and equipment
Property, Plant and Equipment [Line Items]
Gross cost	$ 1,291	$ 1,308