Pension, Retiree Medical and Savings Plans (Selected Information About Plans with Liability for Service to Date and Total Benefit Liability in Excess of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
United States Pension Plan of US Entity, Defined Benefit
Selected information for plans with accumulated benefit obligation in excess of plan assets
Liability for service to date	$ (6,536)	$ (661)
Fair value of plan assets	5,698	2
Selected information for plans with projected benefit liability in excess of plan assets
Benefit liability	(13,033)	(7,385)
Fair value of plan assets	11,397	6,103
Defined Benefit Plan, Fair Value of Plan Assets	11,397	12,224	$ 11,462
International
Selected information for plans with accumulated benefit obligation in excess of plan assets
Liability for service to date	(155)	(333)
Fair value of plan assets	112	288
Selected information for plans with projected benefit liability in excess of plan assets
Benefit liability	(511)	(2,865)
Fair value of plan assets	406	2,583
Defined Benefit Plan, Fair Value of Plan Assets	2,823	3,002	2,777
Retiree Medical Plan
Selected information for plans with projected benefit liability in excess of plan assets
Benefit liability	(1,300)	(1,439)
Fair value of plan assets		415
Defined Benefit Plan, Fair Value of Plan Assets	$ 354	$ 415	$ 406

Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 30
-Section 35
-Paragraph 50
-URI http://asc.fasb.org/extlink&oid=49178875&loc=d3e12355-114930

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

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- Definition

If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=58242635&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2417-114920

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If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

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If aggregate disclosures are presented, the aggregate benefit obligation for plans with benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2417-114920

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If aggregate disclosures are presented, the aggregate fair value of plan assets for plans with benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

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