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
	Oct. 01, 2016	Oct. 03, 2015		Sep. 27, 2014
Fair value of plans' assets
Beginning fair value	$ 9,983
Contributions	900
Ending fair value	11,015	$ 9,983
Amounts recognized in the balance sheet
Non-current liabilities	(5,184)	(3,940)
Net balance sheet liability	(5,224)
Pension Plans
Projected benefit obligations
Beginning obligations	(12,379)	(12,190)
Service cost	(318)	(332)		$ (277)
Interest cost	(458)	(521)		(488)
Actuarial gain / (loss)	(1,769)	(176)
Plan amendments and other	8	28
Benefits paid	436	812	[1]
Ending obligations	(14,480)	(12,379)		(12,190)
Fair value of plans' assets
Beginning fair value	9,415	9,765
Actual return on plan assets	624	163
Contributions	839	337
Benefits paid	(436)	(812)	[1]
Expenses and other	(41)	(38)
Ending fair value	10,401	9,415		9,765
Underfunded status of the plans	(4,079)	(2,964)
Amounts recognized in the balance sheet
Non-current assets	0	3
Current liabilities	(40)	(36)
Non-current liabilities	(4,039)	(2,931)
Net balance sheet liability	(4,079)	(2,964)
Postretirement Medical Plans
Projected benefit obligations
Beginning obligations	(1,590)	(1,567)
Service cost	(11)	(14)		(10)
Interest cost	(61)	(68)		(65)
Actuarial gain / (loss)	(142)	33
Plan amendments and other	(9)	(9)
Benefits paid	54	35	[1]
Ending obligations	(1,759)	(1,590)		(1,567)
Fair value of plans' assets
Beginning fair value	568	538
Actual return on plan assets	34	9
Contributions	61	48
Benefits paid	(54)	(35)	[1]
Expenses and other	(5)	(8)
Ending fair value	614	568		$ 538
Underfunded status of the plans	(1,145)	(1,022)
Amounts recognized in the balance sheet
Non-current assets	0	0
Current liabilities	0	(13)
Non-current liabilities	(1,145)	(1,009)
Net balance sheet liability	$ (1,145)	(1,022)
Pension Plan limited time offer
Projected benefit obligations
Benefits paid		340
Fair value of plans' assets
Benefits paid		$ (340)

[1] Fiscal 2015 pension plans include $340 million of payments under a plan offered for a limited time to certain former employees who had 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.