Debt and Credit Agreements (Long-term Debt Instruments) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 25, 2015	Dec. 26, 2014
Debt Instrument [Line Items]
Subtotal Long-term Debt (including current portion)	$ 10,703	$ 9,742
Less Debt Due within One Year	(20)	(228)
Long-term Debt (excluding current portion)	$ 10,683	9,514
Notes [Member]
Debt Instrument [Line Items]
Average Interest Rates (in hundredths)	5.20%
Subtotal Long-term Debt (including current portion)	$ 10,445	9,456
Equipment Obligations [Member]
Debt Instrument [Line Items]
Average Interest Rates (in hundredths)	6.30%
Subtotal Long-term Debt (including current portion)	$ 250	277
Capital Leases [Member]
Debt Instrument [Line Items]
Average Interest Rates (in hundredths)	15.00%
Subtotal Long-term Debt (including current portion)	$ 7	8
Convertible Debt [Member]
Debt Instrument [Line Items]
Average Interest Rates (in hundredths)	1.00%
Subtotal Long-term Debt (including current portion)	$ 1	$ 1

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13,16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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- Definition

The average effective interest rate during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

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No definition available.

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- Definition

Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 6
-Section H

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- Definition

Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

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