Equity Changes in Accumulated Other Comprehensive Loss, Before Tax (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 28, 2024	Dec. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI before Tax, Attributable to Parent, Beginning Balance	$ (4,417)	$ (3,887)
Unrealized gains (losses) arising during the period	313	(143)
Reclassifications of realized net (gains) losses to net income	(55)	(164)
AOCI reclassifications to comprehensive income, before tax	904
AOCI before Tax, Attributable to Parent, Ending Balance	(3,255)	(4,194)
Market Value Adjustments for Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI before Tax, Attributable to Parent, Beginning Balance	(319)	259
Unrealized gains (losses) arising during the period	559	(277)
Reclassifications of realized net (gains) losses to net income	(88)	(140)
AOCI reclassifications to comprehensive income, before tax	0
AOCI before Tax, Attributable to Parent, Ending Balance	152	(158)
Unrecognized Pension and  Postretirement Medical  Expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI before Tax, Attributable to Parent, Beginning Balance	(2,243)	(2,172)
Unrealized gains (losses) arising during the period	0	(3)
Reclassifications of realized net (gains) losses to net income	33	(24)
AOCI reclassifications to comprehensive income, before tax	0
AOCI before Tax, Attributable to Parent, Ending Balance	(2,210)	(2,199)
Foreign Currency Translation and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI before Tax, Attributable to Parent, Beginning Balance	(1,855)	(1,974)
Unrealized gains (losses) arising during the period	(246)	137
Reclassifications of realized net (gains) losses to net income	0	0
AOCI reclassifications to comprehensive income, before tax	904
AOCI before Tax, Attributable to Parent, Ending Balance	$ (1,197)	$ (1,837)