Schedule of Quarterly Financial Data (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 27, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Quarterly Financial Data [Line Items]
Pre-tax Merger, restructuring, and other operating expenses	$ 58	$ 111	$ 120	$ 43	$ 128	$ 72	$ 103	$ 101	$ 332	$ 403	$ 201
Assets impairments	$ 3	$ 1	$ 4	$ 5	$ 11	6	22	$ 50	$ 13	88	$ 70
Legal accrual						$ 1	$ 80			$ 81

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration