Reconciliation of Segment Operating Income to Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 26, 2016	Mar. 28, 2015	Mar. 26, 2016	Mar. 28, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income	$ 13,987	$ 18,278	$ 38,158	$ 42,524
Research and development expense	(2,511)	(1,918)	(4,915)	(3,813)
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income	17,561	21,311	45,206	48,597
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Research and development expense	(2,511)	(1,918)	(4,915)	(3,813)
Corporate Non-Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other corporate expenses, net	$ (1,063)	$ (1,115)	$ (2,133)	$ (2,260)