Interim Financial Results (Footnotes) (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Selling and administrative expenses				$ 12						$ 1,723		$ 1,621	$ 1,458
Litigation settlement					$ 9					0		354	0
Litigation settlement recovery		$ (5)
Environmental remediation reserve adjustment			$ 9
Restructuring and other charges, net										29		67	54
Amortization of Weyerhaeuser inventory fair value step-up									$ 14
Holmen bargain purchase gain										0		(6)	0
Abandoned property removal		8	6	9	9	$ 6	$ 7	$ 5	2
Amortization expense related to intangible assets							10			59		77	54
Brazil Packaging impairment			122							122		9	70
Non-operating pension expense		429	25	36	4	386	33	34	31			484	610
Interest income on income tax refund claims						(1)		(4)
Pre-tax charges (gains)		414	167	83	44	492	56	387	45
Net (gains) losses on sales and impairments of businesses										122		9	70
Tax Adjustments, Settlements, and Unusual Provisions		25	0	9		9
International investment restructuring	[1]	19
Tax impact of other special items		3	(46)	(13)	(9)	(41)	(8)	(137)	(8)
Tax impact of non-operating pension expense		(107)	(6)	(9)	(1)	(148)	(13)	(13)	(12)
Other Tax Expense (Benefit)		(60)	(88)	(13)	(10)	(1,430)	(2)	(197)	(5)
Income tax refund claims						(28)		(85)
Tax benefit of Tax Cuts and Jobs Act						(1,220)						(1,220)
North American Consumer Packaging [Member]
Business Acquisition [Line Items]
Non-operating pension expense				28	(516)	45
Pre-tax charges (gains)				30	(493)	62
North American Consumer Packaging transaction costs				2	23	17
Asia Foodservice [Member]
Business Acquisition [Line Items]
Asia Foodservice sale								9
IP Asia Packaging [Member]
Business Acquisition [Line Items]
Asia Foodservice sale													46
Riegelwood mill conversion costs
Business Acquisition [Line Items]
Restructuring and other charges, net								(14)				(14)
EMEA Industrial Packaging [Member]
Business Acquisition [Line Items]
Restructuring and other charges, net		(1)		$ 26	$ 22					47	[2]
Riverdale mill conversion [Member]
Business Acquisition [Line Items]
Restructuring and other charges, net	[1]	4	5							3
India packaging evaluation write-off
Business Acquisition [Line Items]
Restructuring and other charges, net													17
Early debt extinguishment costs (see Note 13)
Business Acquisition [Line Items]
Restructuring and other charges, net		10				83				10		83	29
Gain on sale of investment in Arizona Chemical
Business Acquisition [Line Items]
Restructuring and other charges, net													(8)
Other items
Business Acquisition [Line Items]
Restructuring and other charges, net								(2)				(2)
Turkey mill closure
Business Acquisition [Line Items]
Restructuring and other charges, net	[3]												7
Gain on sale of investment in Liaison Technologies Inc.
Business Acquisition [Line Items]
Restructuring and other charges, net		$ (31)								$ (31)
Weyerhaeuser Pulp Business [Member]
Business Acquisition [Line Items]
Costs associated with the newly acquired pulp business						$ 18	6	5	4				28
Amortization of Weyerhaeuser inventory fair value step-up													33
Holmen Paper Newsprint Mill [Member]
Business Acquisition [Line Items]
Holmen bargain purchase gain									(6)				$ (6)
Internal Restructuring [Member]
Business Acquisition [Line Items]
Other Tax Expense (Benefit)							$ 19		$ 15
Cash pension contribution
Business Acquisition [Line Items]
Other Tax Expense (Benefit)								38
Kleen Products Llc Versus Packaging Corp Of America [Member]
Business Acquisition [Line Items]
Litigation settlement								$ 354
Tax Cuts and Jobs Act [Member]
Business Acquisition [Line Items]
Tax benefit of Tax Cuts and Jobs Act			$ (36)									$ (1,454)

[1] Includes severance related to 51 employees.

[2] Includes $33 million of severance, $6 million in accelerated depreciation, $2 million in accelerated amortization and $6 million in other charges in conjunction with the optimization of our EMEA Packaging business. The majority of the severance charges recorded were paid throughout the year.

[3] Includes $4 million of accelerated depreciation and $3 million of severance charges which is related to 85 employees.