Pension and Other Benefit Programs - Benefit Obligations, Assets, Funded Status and Balance Sheet Impacts Associated with Pension and Postretirement Medical Benefit Plans based upon Actuarial Valuations (Detail) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2023	Oct. 01, 2022	Oct. 02, 2021
Fair value of plans' assets
Contributions		$ 102
Amounts recognized in the balance sheet
Net balance sheet liability (asset)		572
Pension Plans
Projected benefit obligations
Beginning obligations		(15,028)	$ (20,955)
Service cost		(282)	(400)	$ (434)
Interest cost		(784)	(500)	(457)
Actuarial gain (loss)	[1]	757	6,159
Plan amendments and other	[2]	14	39
Benefits Paid		633	629
Ending obligations		(14,690)	(15,028)	(20,955)
Fair value of plans' assets
Beginning fair value		14,721	18,076
Actual return on plan assets		1,324	(2,715)
Contributions		73	96
Benefits paid		(633)	(629)
Expenses and other		(43)	(107)
Ending fair value		15,442	14,721	18,076
Underfunded status of the plans		752	(307)
Amounts recognized in the balance sheet
Non-current assets		1,971	913
Current liabilities		(72)	(66)
Non-current liabilities		(1,147)	(1,154)
Net balance sheet liability (asset)		752	(307)
Postretirement Medical Plans
Projected benefit obligations
Beginning obligations		(1,539)	(2,121)
Service cost		(5)	(9)	(10)
Interest cost		(81)	(51)	(47)
Actuarial gain (loss)	[1]	59	595
Plan amendments and other	[2]	539	(16)
Benefits Paid		66	63
Ending obligations		(961)	(1,539)	(2,121)
Fair value of plans' assets
Beginning fair value		749	889
Actual return on plan assets		71	(134)
Contributions		29	61
Benefits paid		(66)	(63)
Expenses and other		(2)	(4)
Ending fair value		781	749	$ 889
Underfunded status of the plans		(180)	(790)
Amounts recognized in the balance sheet
Non-current assets		209	0
Current liabilities		(2)	(4)
Non-current liabilities		(387)	(786)
Net balance sheet liability (asset)		$ (180)	$ (790)

[1] The actuarial gain for fiscal 2022 was due to an increase in the discount rate used to determine the fiscal year-end benefit obligation from the rate that was used in the preceding fiscal year.

[2] The decrease in fiscal 2023 was due to a change in postretirement medical benefit options.