Acquisitions (Details) (USD $)	12 Months Ended
	Sep. 25, 2011	Sep. 26, 2010	Sep. 27, 2009
Acquisition [Abstract]
Effective date of Atheros acquisition	5/24/2011
Total cash consideration, net of cash acquired	$ 3,100,000,000
Cash acquired from Atheros acquisition	233,000,000
Assumed equity	106,000,000
Business Acquisition, Purchase Price Allocation [Abstract]
Acquisition cost	23,000,000
Number of other businesses acquired	9	6	1
Cash consideration paid for other businesses acquired	466,000,000	50,000,000	17,000,000
Acquired technology-based intangible assets	150,000,000	32,000,000
Technology-based intangible asset, weighted average useful life	5	11
Goodwill recognized from other businesses acquired, expected to be deductible for tax purposes	$ 234,000,000