Financial Instruments - Additional Information (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 24, 2016	Jun. 26, 2015	Jun. 24, 2016	Jun. 26, 2015	Sep. 25, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) reported in accumulated other comprehensive loss	$ 7	$ 25	$ (21)	$ (349)
Unrealized gains (losses) related to available-for-sale securities	4	(6)	9	(6)
Unrealized gains related to trading securities	0	1	2	5
1.375% public notes due 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) reported in accumulated other comprehensive loss	(6)	$ (12)	(6)	$ 8
Foreign Exchange Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross notional amount of foreign exchange contracts	$ 614		$ 614		$ 365