Equity Changes in Accumulated Other Comprehensive Loss, Tax (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Tax, Attributable to Parent, Beginning Balance		$ 1,841	$ 1,048	$ 1,842	$ 1,752
Other Comprehensive Income (Loss) before Reclassifications, Tax		49	3	88	1
Reclassification from AOCI, Current Period, Tax		(13)	(3)	(53)	(22)
AOCI reclassifications to retained earnings, tax	[1]				(683)
AOCI Tax, Attributable to Parent, Ending Balance		1,877	1,048	1,877	1,048
Accumulated Net Gain (Loss) from Market Value Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Tax, Attributable to Parent, Beginning Balance	[2]	(36)	(13)	(29)	(41)
Other Comprehensive Income (Loss) before Reclassifications, Tax	[2]	19	(10)	(12)	4
Reclassification from AOCI, Current Period, Tax	[2]	18	13	42	27
AOCI reclassifications to retained earnings, tax	[1],[2]				0
AOCI Tax, Attributable to Parent, Ending Balance	[2]	1	(10)	1	(10)
Unrecognized Pension and  Postretirement Medical  Expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Tax, Attributable to Parent, Beginning Balance		1,702	984	1,756	1,690
Other Comprehensive Income (Loss) before Reclassifications, Tax		2	8	12	2
Reclassification from AOCI, Current Period, Tax		(31)	(16)	(95)	(49)
AOCI reclassifications to retained earnings, tax	[1]				(667)
AOCI Tax, Attributable to Parent, Ending Balance		1,673	976	1,673	976
Foreign Currency Translation and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Tax, Attributable to Parent, Beginning Balance		175	77	115	103
Other Comprehensive Income (Loss) before Reclassifications, Tax		28	5	88	(5)
Reclassification from AOCI, Current Period, Tax		0	0	0	0
AOCI reclassifications to retained earnings, tax	[1]				(16)
AOCI Tax, Attributable to Parent, Ending Balance		$ 203	$ 82	$ 203	$ 82

[1] At the beginning of fiscal 2019, the Company adopted new FASB accounting guidance, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, and reclassified $691 million from AOCI to retained earnings.In addition, at the beginning of fiscal 2019, the Company adopted new FASB accounting guidance, Recognition and Measurement of Financial Assets and Liabilities, and reclassified $24 million ($15 million after tax) of market value adjustments on investments previously recorded in AOCI to retained earnings.

[2] Primarily reflects market value adjustments for cash flow hedges.