Pension and Other Benefit Programs - Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	12 Months Ended
	Oct. 01, 2016	Oct. 03, 2015	Sep. 27, 2014
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 318	$ 332	$ 277
Interest cost	458	521	488
Expected return on plan assets	(747)	(711)	(645)
Amortization of prior year service costs	14	16	14
Recognized net actuarial loss / (gain)	242	247	145
Net periodic benefit cost	285	405	279
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	11	14	10
Interest cost	61	68	65
Expected return on plan assets	(45)	(39)	(36)
Amortization of prior year service costs	(1)	(1)	(2)
Recognized net actuarial loss / (gain)	8	10	(7)
Net periodic benefit cost	$ 34	$ 52	$ 30