Benefit Plans - Additional Information (Detail) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 25, 2016 USD ($) $ / shares shares	Jun. 27, 2015 USD ($)	Jun. 25, 2016 USD ($) $ / shares shares	Jun. 27, 2015 USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares reserved for future issuance under stock plans (in shares) | shares	386,300,000		386,300,000
RSUs granted vesting period			4 years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of vested RSUs as of vesting date	$ 2,000	$ 2,300	$ 4,500	$ 4,300
Stock options outstanding (in shares) | shares	1,100,000		1,100,000
Stock options, weighted average exercise price per share (in USD per share) | $ / shares	$ 15.69		$ 15.69
Stock options, weighted average remaining contractual term			3 years 4 months 12 days
Stock options, aggregate intrinsic value	$ 84		$ 84
Income tax benefit related to share-based compensation expense	321	$ 286	1,100	$ 948
Total unrecognized compensation cost on stock options and RSUs	$ 8,300		$ 8,300
Total unrecognized compensation cost on stock options and RSUs, weighted-average recognition period (in years)			2 years 8 months 24 days
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common stock issued per RSU upon vesting			1
Reduction in number of shares available for grant per share issued with respect to RSUs granted | shares			2
Increase in number of shares available for grant per RSU cancelled or withheld for tax withholding			2
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Impact on shares available for grant per stock option granted			1