Equity Changes in Accumulated Other Comprehensive Loss, Tax (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Tax, Attributable to Parent, Beginning Balance	$ 1,048	$ 1,876	$ 1,752	$ 1,994
Other Comprehensive Income (Loss) before Reclassifications, Tax	3	(20)	1	(63)
Reclassification from AOCI, Current Period, Tax	(3)	(30)	(22)	(105)
AOCI reclassifications to retained earnings, tax			(683)
AOCI Tax, Attributable to Parent, Ending Balance	1,048	1,826	1,048	1,826
Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Tax, Attributable to Parent, Beginning Balance	1	(10)	(9)	(7)
Other Comprehensive Income (Loss) before Reclassifications, Tax	(3)	0	(2)	(3)
Reclassification from AOCI, Current Period, Tax	0	0	0	0
AOCI reclassifications to retained earnings, tax			9
AOCI Tax, Attributable to Parent, Ending Balance	(2)	(10)	(2)	(10)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Tax, Attributable to Parent, Beginning Balance	(14)	41	(32)	46
Other Comprehensive Income (Loss) before Reclassifications, Tax	(7)	(56)	6	(44)
Reclassification from AOCI, Current Period, Tax	13	(6)	27	(23)
AOCI reclassifications to retained earnings, tax			(9)
AOCI Tax, Attributable to Parent, Ending Balance	(8)	(21)	(8)	(21)
Unrecognized Pension and Postretirement Medical Expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Tax, Attributable to Parent, Beginning Balance	984	1,778	1,690	1,839
Other Comprehensive Income (Loss) before Reclassifications, Tax	8	(2)	2	(5)
Reclassification from AOCI, Current Period, Tax	(16)	(24)	(49)	(82)
AOCI reclassifications to retained earnings, tax			(667)
AOCI Tax, Attributable to Parent, Ending Balance	976	1,752	976	1,752
Foreign Currency Translation and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Tax, Attributable to Parent, Beginning Balance	77	67	103	116
Other Comprehensive Income (Loss) before Reclassifications, Tax	5	38	(5)	(11)
Reclassification from AOCI, Current Period, Tax	0	0	0	0
AOCI reclassifications to retained earnings, tax			(16)
AOCI Tax, Attributable to Parent, Ending Balance	$ 82	$ 105	$ 82	$ 105