(Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Postretirement benefit accruals	$ 90	$ 89
Pension obligations	421	465
Tax credits	290	291
Net operating and capital loss carryforwards	621	594
Compensation reserves	181	191
Lease obligations	106	0
Environmental reserves	93	78
Other	126	86
Gross deferred income tax assets	1,928	1,794
Less: valuation allowance (a)	(691)	(441)
Net deferred income tax asset	1,237	1,353
Intangibles	(152)	(152)
Investments	(265)	(255)
Right of use assets	(106)	0
Plants, properties and equipment	(1,866)	(1,826)
Forestlands, related installment sales, and investment in subsidiary	(1,407)	(1,453)
Gross deferred income tax liabilities	(3,796)	(3,686)
Net deferred income tax liability	$ (2,559)	$ (2,333)