Segment Information and Geographic Data - Reconciliation of Segment Operating Income to Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income	$ 23,359	$ 24,171
Research and development expense	(2,871)	(2,404)
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income	27,308	27,645
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Research and development expense	(2,871)	(2,404)
Corporate Non-Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other corporate expenses, net	$ (1,078)	$ (1,070)