Financial Instruments - Derivative Instruments at Gross Fair Value (Detail) - Level 2 - USD ($) $ in Millions	Jun. 25, 2016	Sep. 26, 2015
Foreign exchange contracts | Other Current Assets
Derivative assets:
Fair value of derivative assets	$ 506	$ 1,551
Foreign exchange contracts | Accrued expenses
Derivative liabilities:
Fair value of derivative liabilities	1,184	999
Interest rate contracts | Other Current Assets
Derivative assets:
Fair value of derivative assets	860	394
Interest rate contracts | Accrued expenses
Derivative liabilities:
Fair value of derivative liabilities	4	13
Derivatives Designated as Hedging Instruments | Foreign exchange contracts | Other Current Assets
Derivative assets:
Fair value of derivative assets	391	1,442
Derivatives Designated as Hedging Instruments | Foreign exchange contracts | Accrued expenses
Derivative liabilities:
Fair value of derivative liabilities	903	905
Derivatives Designated as Hedging Instruments | Interest rate contracts | Other Current Assets
Derivative assets:
Fair value of derivative assets	860	394
Derivatives Designated as Hedging Instruments | Interest rate contracts | Accrued expenses
Derivative liabilities:
Fair value of derivative liabilities	4	13
Not Designated as Hedging Instrument | Foreign exchange contracts | Other Current Assets
Derivative assets:
Fair value of derivative assets	115	109
Not Designated as Hedging Instrument | Foreign exchange contracts | Accrued expenses
Derivative liabilities:
Fair value of derivative liabilities	281	94
Not Designated as Hedging Instrument | Interest rate contracts | Other Current Assets
Derivative assets:
Fair value of derivative assets	0	0
Not Designated as Hedging Instrument | Interest rate contracts | Accrued expenses
Derivative liabilities:
Fair value of derivative liabilities	$ 0	$ 0