Pension and Other Benefit Programs - Additional Information (Detail) - USD ($) $ in Millions		12 Months Ended
		Oct. 03, 2015	Sep. 27, 2014	Sep. 28, 2013
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		$ 11,500	$ 9,700
Pension plans with accumulated benefit obligations in excess of plan assets, accumulated benefit obligation		10,600	8,800
Pension plans with accumulated benefit obligations in excess of plan assets, aggregate fair value of plan assets		8,500	7,200
Total accumulated pension benefit obligations		$ 11,400	$ 11,200
Total accumulated pension benefit obligations, vested percentage		98.00%	98.00%
Additional Capital Contributions Commitment		$ 679
Pension and postretirement medical plans, employer contributions		$ 385
Defined contribution plan, contribution rate		50.00%
Savings and investment plans, employees contribution rate		50.00%
Defined contribution plans, employer contributions		$ 110	$ 87	$ 68
Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected pension and postretirement medical plan contributions in fiscal 2015		$ 900
Defined contribution plan, contribution rate		3.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Expected pension and postretirement medical plan contributions in fiscal 2015		$ 950
Defined contribution plan, contribution rate		9.00%
Pension Plan limited time offer [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefits paid		$ 340
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Benefits paid	[1]	812	306
Postretirement medical plans with accumulated postretirement medical benefit obligations in excess of plan assets, accumulated benefit obligations		12,400	9,700
Postretirement medical plans with accumulated postretirement medical benefit obligations in excess of plan assets, fair value of plan assets		9,400	7,200
Pension and postretirement medical plans, employer contributions		337	258
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Benefits paid		35	44
Postretirement medical plans with accumulated postretirement medical benefit obligations in excess of plan assets, accumulated benefit obligations		1,600	1,600
Postretirement medical plans with accumulated postretirement medical benefit obligations in excess of plan assets, fair value of plan assets		600	500
Pension and postretirement medical plans, employer contributions		$ 48	$ 17
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year		7.00%	7.00%	7.25%
Rate of increase to which the cost of benefits is assumed to decline (the ultimate trend rate)		4.25%	4.25%	4.25%

[1] Fiscal 2015 pension plans include $340 million of payments under a plan offered for a limited time to certain former employees who have vested benefits in our qualified defined benefit pension plans. These employees elected to receive an immediate lump-sum distribution in lieu of benefits they would have received following their retirement.