Changes in Accumulated Other Comprehensive Loss, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 02, 2022	Apr. 03, 2021	Apr. 02, 2022	Apr. 03, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	$ (6,276)	$ (8,141)	$ (6,440)	$ (8,322)
Unrealized gains (losses) arising during the period	(139)	71	(80)	137
Reclassifications of realized net (gains) losses to net income	103	152	208	267
AOCI, Ending Balance	(6,312)	(7,918)	(6,312)	(7,918)
Market Value Adjustments for Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	(60)	(324)	(110)	(151)
Unrealized gains (losses) arising during the period	44	107	108	(32)
Reclassifications of realized net (gains) losses to net income	(16)	3	(30)	(31)
AOCI, Ending Balance	(32)	(214)	(32)	(214)
Unrecognized Pension and  Postretirement Medical  Expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	(5,217)	(7,072)	(5,372)	(7,222)
Unrealized gains (losses) arising during the period	0	42	36	43
Reclassifications of realized net (gains) losses to net income	119	149	238	298
AOCI, Ending Balance	(5,098)	(6,881)	(5,098)	(6,881)
Foreign Currency Translation and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	(999)	(745)	(958)	(949)
Unrealized gains (losses) arising during the period	(183)	(78)	(224)	126
Reclassifications of realized net (gains) losses to net income	0	0	0	0
AOCI, Ending Balance	$ (1,182)	$ (823)	$ (1,182)	$ (823)