Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 25, 2015	Sep. 26, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax.
Balance at the beginning of the period	$ (373)	$ (17)	$ 303
Other comprehensive loss before reclassifications	(273)	(727)	(462)
Amounts reclassified from accumulated other comprehensive income (loss)	79	344	98
Income tax (expense) benefit	25	27	44
Other comprehensive loss	(169)	(356)	(320)
Balance at the end of the period	(542)	(373)	(17)
Currency Translation
Accumulated Other Comprehensive Income (Loss), Net of Tax.
Balance at the beginning of the period	408	720	931
Other comprehensive loss before reclassifications	(69)	(536)	(216)
Amounts reclassified from accumulated other comprehensive income (loss)	(23)	224	5
Other comprehensive loss	(92)	(312)	(211)
Balance at the end of the period	316	408	720
Unrecognized Pension and Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss), Net of Tax.
Balance at the beginning of the period	(738)	(692)	(569)
Other comprehensive loss before reclassifications	(190)	(147)	(211)
Amounts reclassified from accumulated other comprehensive income (loss)	70	75	44
Income tax (expense) benefit	32	26	44
Other comprehensive loss	(88)	(46)	(123)
Balance at the end of the period	(826)	(738)	(692)
Gain (Loss) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax.
Balance at the beginning of the period	(43)	(45)	(59)
Other comprehensive loss before reclassifications	(14)	(44)	(35)
Amounts reclassified from accumulated other comprehensive income (loss)	32	45	49
Income tax (expense) benefit	(7)	1
Other comprehensive loss	11	2	14
Balance at the end of the period	(32)	(43)	(45)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax.
Other comprehensive loss	$ (169)	$ (356)	$ (320)