Pension and Other Benefit Programs - Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	12 Months Ended
	Oct. 02, 2021	Oct. 03, 2020	Sep. 28, 2019
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ 350
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	434	$ 410	$ 345
Interest cost	457	527	592
Expected return on plan assets	(1,100)	(1,084)	(978)
Amortization of prior-year service costs	11	13	13
Recognized net actuarial loss	777	544	260
Total other costs (benefits)	145	0	(113)
Net periodic benefit cost	579	410	232
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	10	10	8
Interest cost	47	56	67
Expected return on plan assets	(55)	(57)	(56)
Amortization of prior-year service costs	0	0	0
Recognized net actuarial loss	30	14	0
Total other costs (benefits)	22	13	11
Net periodic benefit cost	$ 32	$ 23	$ 19