Equity Changes in Accumulated Other Comprehensive Loss, Before Tax (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 02, 2022	Jul. 03, 2021	Jul. 02, 2022	Jul. 03, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI before Tax, Attributable to Parent, Beginning Balance	$ (7,999)	$ (10,222)	$ (8,224)	$ (10,702)
Unrealized gains (losses) arising during the period	197	(24)	151	106
Reclassifications of realized net (gains) losses to net income	128	198	399	548
AOCI before Tax, Attributable to Parent, Ending Balance	(7,674)	(10,048)	(7,674)	(10,048)
Market Value Adjustments for Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI before Tax, Attributable to Parent, Beginning Balance	(51)	(283)	(152)	(191)
Unrealized gains (losses) arising during the period	601	(1)	741	(55)
Reclassifications of realized net (gains) losses to net income	(27)	4	(66)	(34)
AOCI before Tax, Attributable to Parent, Ending Balance	523	(280)	523	(280)
Unrecognized Pension and  Postretirement Medical  Expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI before Tax, Attributable to Parent, Beginning Balance	(6,668)	(8,978)	(7,025)	(9,423)
Unrealized gains (losses) arising during the period	0	29	47	86
Reclassifications of realized net (gains) losses to net income	155	194	465	582
AOCI before Tax, Attributable to Parent, Ending Balance	(6,513)	(8,755)	(6,513)	(8,755)
Foreign Currency Translation and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI before Tax, Attributable to Parent, Beginning Balance	(1,280)	(961)	(1,047)	(1,088)
Unrealized gains (losses) arising during the period	(404)	(52)	(637)	75
Reclassifications of realized net (gains) losses to net income	0	0	0	0
AOCI before Tax, Attributable to Parent, Ending Balance	$ (1,684)	$ (1,013)	$ (1,684)	$ (1,013)