Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Postretirement benefit accruals	$ 189	$ 193
Pension obligations	1,517	725
Alternative minimum and other tax credits	342	515
Net operating and capital loss carryforwards	672	610
Compensation reserves	280	281
Other	266us-gaap_DeferredTaxAssetsOther	284us-gaap_DeferredTaxAssetsOther
Gross deferred income tax assets	3,266us-gaap_DeferredTaxAssetsGross	2,608us-gaap_DeferredTaxAssetsGross
Less: valuation allowance	(415)	(413)
Net deferred income tax asset	2,851us-gaap_DeferredTaxAssetsNet	2,195us-gaap_DeferredTaxAssetsNet
Deferred tax liabilities, intangible assets	(316)	(304)
Plants, properties and equipment	(2,707)	(2,919)
Forestlands and related installment sales	(2,290)	(2,307)
Gross deferred income tax liabilities	(5,313)	(5,530)
Net deferred income tax liability	$ (2,462)us-gaap_DeferredTaxLiabilities	$ (3,335)us-gaap_DeferredTaxLiabilities

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible alternative minimum tax credit carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from pension benefits.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from postretirement benefits.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances.

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.

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Gross amount of noncurrent deferred tax liabilities, which result from applying the applicable tax rate to taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax.

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Amount of deferred tax liability attributable to taxable temporary differences from long-lived assets other than property, plant, and equipment.

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