Acquisitions Business Acquisition (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Sep. 25, 2011	Sep. 26, 2010
Business Acquisition, Purchase Price Allocation [Abstract]
Weighted-average useful life of intangible assets acquired (in years)	5	11
In-process research and development estimated completion period	3
Atheros Communications, Inc. [Member]
Acquisitions [Abstract]
Current Assets	$ 925
In-process research and development (IPR&D)	150
Goodwill	1,777
Other assets	77
Total assets	3,785
Liabilities	(316)
Total	3,469
Business Acquisition, Purchase Price Allocation [Abstract]
Number of In-process research and development projects	26
In-process research and development estimated costs to complete projects	36
Low range of In-process research and development useful life (in years)	2
High range of In-process research and development useful life (in years)	6
Technology-based [Member]
Acquisitions [Abstract]
Amortizable intangible assets	692
Business Acquisition, Purchase Price Allocation [Abstract]
Weighted-average useful life of intangible assets acquired (in years)	4
Marketing-related [Member]
Acquisitions [Abstract]
Amortizable intangible assets	50
Business Acquisition, Purchase Price Allocation [Abstract]
Weighted-average useful life of intangible assets acquired (in years)	6
Customer-related [Member]
Acquisitions [Abstract]
Amortizable intangible assets	$ 114
Business Acquisition, Purchase Price Allocation [Abstract]
Weighted-average useful life of intangible assets acquired (in years)	3

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The maximum amortization period for in-process research and development projects acquired in a business combination.

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The number of in-process research and development projects acquired in a business combination.

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The calculated weighted-average amortization period of a major class of finite-lived intangible assets acquired during the current period either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

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The amount of acquisition cost of a business combination allocated to an identifiable intangible asset that will be amortized.

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The amount of acquisition cost of a business combination allocated to assets acquired.

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The amount of acquisition cost of a business combination allocated to current assets.

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Amount of goodwill arising from a business combination, which is the excess of the cost of the acquired entity over the amounts assigned to assets acquired and liabilities assumed.

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The amount of acquisition cost of a business combination allocated to liabilities assumed.

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The amount of acquisition cost of a business combination allocated to noncurrent assets of the acquired entity, except for property plant and equipment, intangible assets, and goodwill.

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The net amount recognized as of the acquisition date for the aggregate assets, including goodwill, in excess of or less than the aggregate liabilities assumed. This amount may also be viewed as the incremental amount of equity that the consolidated entity (including the portion attributable to the noncontrolling interest) will recognize as a result of the business combination.

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