Pension and Other Benefit Programs - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016	Oct. 03, 2015
Defined Benefit Plan Disclosure [Line Items]
New vesting service year requirement effective January 1, 2012		3 years
Pension plans with accumulated benefit obligations in excess of plan assets, projected benefit obligation		$ 8,500	$ 13,436
Pension plans with accumulated benefit obligations in excess of plan assets, accumulated benefit obligation		7,700	12,414
Pension plans with accumulated benefit obligations in excess of plan assets, aggregate fair value of plan assets		6,400	9,468
Total accumulated pension benefit obligations		$ 13,400	$ 13,300
Total accumulated pension benefit obligations, vested percentage		99.00%	99.00%
Additional Capital Contributions Commitment		$ 788
Pension and postretirement medical plans, employer contributions		$ 1,400
Defined contribution plan, contribution rate		50.00%
Savings and investment plans, employees contribution rate		50.00%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, contribution rate		3.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, contribution rate		9.00%
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Postretirement medical plans with accumulated postretirement medical benefit obligations in excess of plan assets, accumulated benefit obligations		$ 12,800	$ 14,500
Postretirement medical plans with accumulated postretirement medical benefit obligations in excess of plan assets, fair value of plan assets		10,500	10,400
Pension and postretirement medical plans, employer contributions		1,348	839
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Postretirement medical plans with accumulated postretirement medical benefit obligations in excess of plan assets, accumulated benefit obligations		1,700	1,800
Postretirement medical plans with accumulated postretirement medical benefit obligations in excess of plan assets, fair value of plan assets		700	600
Pension and postretirement medical plans, employer contributions		$ 61	$ 61
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year		7.00%	7.00%	7.00%
Rate of increase to which the cost of benefits is assumed to decline (the ultimate trend rate)		4.25%	4.25%	4.25%
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plans, employer contributions		$ 143	$ 131	$ 110
Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plans, employer contributions		$ 20	$ 19	$ 19
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Decrease in Defined Benefit and Postretirement Medical Cost	$ 63
Defined Benefit and Post Retirement Medical Cost	$ 330