Reconciliation of Segment Operating Income to Condensed Consolidated Statements of Operations (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 28, 2015	Mar. 29, 2014	Mar. 28, 2015	Mar. 29, 2014
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income	$ 18,278us-gaap_OperatingIncomeLoss	$ 13,593us-gaap_OperatingIncomeLoss	$ 42,524us-gaap_OperatingIncomeLoss	$ 31,056us-gaap_OperatingIncomeLoss
Research and development expense	(1,918)us-gaap_ResearchAndDevelopmentExpense	(1,422)us-gaap_ResearchAndDevelopmentExpense	(3,813)us-gaap_ResearchAndDevelopmentExpense	(2,752)us-gaap_ResearchAndDevelopmentExpense
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income	21,311	15,911	48,597	35,548
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Research and development expense	(1,918)	(1,422)	(3,813)	(2,752)
Corporate Non-Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other corporate expenses, net	$ (1,115)	$ (896)	$ (2,260)	$ (1,740)

- Definition

The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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