(Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Postretirement benefit accruals		$ 91	$ 90
Pension obligations		288	421
Tax credits		296	290
Net operating and capital loss carryforwards		590	621
Compensation reserves		179	181
Lease obligations		114	106
Environmental reserves		117	93
Other		218	126
Gross deferred income tax assets		1,893	1,928
Less: valuation allowance (a)	[1]	(685)	(691)
Net deferred income tax asset		1,208	1,237
Intangibles		(159)	(152)
Investments		(251)	(265)
Right of use assets		(114)	(106)
Plants, properties and equipment		(1,958)	(1,866)
Forestlands, related installment sales, and investment in subsidiary		(1,400)	(1,407)
Gross deferred income tax liabilities		(3,882)	(3,796)
Net deferred income tax liability		$ (2,674)	$ (2,559)

[1] The net change in the total valuation allowance for the years ended December 31, 2020 and 2019 was a decrease of $(6) million and an increase of $250 million, respectively. The net change in the prior year is primarily due to tax law changes in foreign jurisdictions impacting future utilization of deferred tax assets of $203 million.