Changes in Accumulated Other Comprehensive Loss, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 29, 2025	Mar. 30, 2024	Mar. 29, 2025	Mar. 30, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	$ (2,688)	$ (3,502)	$ (3,699)	$ (3,292)
Unrealized gains (losses) arising during the period	(124)	82	83	(2)
Reclassifications of realized net (gains) losses to net income	(65)	(89)	(107)	(215)
AOCI reclassifications to comprehensive income, net of tax			846
AOCI, Ending Balance	(2,877)	(3,509)	(2,877)	(3,509)
Market Value Adjustments for Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	114	(124)	(248)	195
Unrealized gains (losses) arising during the period	(163)	186	266	(25)
Reclassifications of realized net (gains) losses to net income	(90)	(71)	(157)	(179)
AOCI reclassifications to comprehensive income, net of tax			0
AOCI, Ending Balance	(139)	(9)	(139)	(9)
Unrecognized Pension and  Postretirement Medical  Expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	(1,687)	(1,676)	(1,712)	(1,655)
Unrealized gains (losses) arising during the period	(7)	(6)	(7)	(9)
Reclassifications of realized net (gains) losses to net income	25	(18)	50	(36)
AOCI reclassifications to comprehensive income, net of tax			0
AOCI, Ending Balance	(1,669)	(1,700)	(1,669)	(1,700)
Foreign Currency Translation and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	(1,115)	(1,702)	(1,739)	(1,832)
Unrealized gains (losses) arising during the period	46	(98)	(176)	32
Reclassifications of realized net (gains) losses to net income	0	0	0	0
AOCI reclassifications to comprehensive income, net of tax			846
AOCI, Ending Balance	$ (1,069)	$ (1,800)	$ (1,069)	$ (1,800)