Interim Financial Results (Footnotes) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Business Acquisition [Line Items]
Other Tax Expense (Benefit)	$ (1,282)	$ 11	$ (184)	$ 7	$ 17	$ (24)	$ 7	$ (74)
Proceeds from Income Tax Refunds	(28)		(85)
Increase (Decrease) in Accrued Taxes Payable			38
Tax Adjustments, Settlements, and Unusual Provisions	9
Tax Cuts and Jobs Act of 2017, Income Tax Expense Benefit, Incomplete Accounting, Provisional Amount	(1,222)								$ 1,220
Payments for Legal Settlements								8
Restructuring and other charges									67	$ 54		$ 252
Non-operating pension expense	386	33	34	31	37	42	487	44	484	610		258
Interest Income, Income tax settlement	(1)		(4)
Write-off of certain regulatory pre-engineering costs						8
Net (gains) losses on sales and impairments of businesses						5	28	37	9	70		174
Amortization expense related to intangible assets		10							77	54		60
Tax audits									0	(14)		0
Pre-tax charges (gains)	492	56	387	45	82	108	520	82
Inventory adjustment				14	19
Net bargain purchase gain on acquisition of business									(6)	0		0
Payments for Removal Costs	6	7	5	2
Litigation settlement									354	0		0
Special Items [Member]
Business Acquisition [Line Items]
Income tax provision (benefit) related to special items	(41)	(8)	(137)	(8)	(14)	(24)	(10)	(3)
North American Consumer Packaging [Member]
Business Acquisition [Line Items]
Disposal Group, Including Discontinued Operation, Other Expense	17
Non-operating pension expense	45
Pre-tax charges (gains)	62
Asia Foodservice [Member]
Business Acquisition [Line Items]
Impairment of long-lived assets to be disposed of			9
IP Asia Packaging [Member]
Business Acquisition [Line Items]
Impairment of long-lived assets to be disposed of										46
IP-Sun JV [Member]
Business Acquisition [Line Items]
Net (gains) losses on sales and impairments of businesses												174
Riegelwood mill conversion costs
Business Acquisition [Line Items]
Restructuring and other charges			(14)						(14)
India packaging evaluation write-off
Business Acquisition [Line Items]
Restructuring and other charges						17				17
Timber monetization restructuring
Business Acquisition [Line Items]
Restructuring and other charges												16
Early debt extinguishment costs (see Note 13)
Business Acquisition [Line Items]
Restructuring and other charges	83					29			83	29		207
Gain on sale of investment in Arizona Chemical
Business Acquisition [Line Items]
Restructuring and other charges								(8)		(8)
Other items
Business Acquisition [Line Items]
Restructuring and other charges			(2)						(2)			6
Turkey mill closure
Business Acquisition [Line Items]
Restructuring and other charges					7					7	[1]
Weyerhaeuser Pulp Business [Member]
Business Acquisition [Line Items]
Costs associated with the newly acquired pulp business	$ 18	6	5	4	19	$ 7	5			28
Inventory adjustment										$ 33		$ 33
Holmen Paper Newsprint Mill [Member]
Business Acquisition [Line Items]
Net bargain purchase gain on acquisition of business				(6)					$ (6)
Brazil goodwill
Business Acquisition [Line Items]
Other Tax Expense (Benefit)								(57)
Internal Restructuring [Member]
Business Acquisition [Line Items]
Other Tax Expense (Benefit)		$ 19		$ 15			(6)
Cash pension contribution
Business Acquisition [Line Items]
Other Tax Expense (Benefit)							$ 23
Luxembourg tax rate change
Business Acquisition [Line Items]
Other Tax Expense (Benefit)					$ 31
Settlement of tax audits and legislative changes
Business Acquisition [Line Items]
Other Tax Expense (Benefit)								$ (14)
Kleen Products Llc Versus Packaging Corp Of America [Member]
Business Acquisition [Line Items]
Litigation settlement			$ 354

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