Pension and Other Benefit Programs - Defined Benefit Plan Assets Measured at Fair Value (Detail) - USD ($) $ in Millions		Sep. 28, 2019	Sep. 29, 2018
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		$ 7,931	$ 7,048
Fair value asset measurements		$ 15,640	$ 13,459
Percentage of plan assets mix		100.00%	100.00%
Cash
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		$ 197	$ 57
Percentage of plan assets mix		1.00%	0.00%
Equity Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy	[1]	$ 3,468	$ 3,023
Percentage of plan assets mix	[1]	22.00%	22.00%
Mutual Funds
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		$ 1,140	$ 800
Percentage of plan assets mix		7.00%	6.00%
US Government Debt Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		$ 2,446	$ 2,507
Percentage of plan assets mix		16.00%	19.00%
Corporate Bond Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		$ 580	$ 573
Percentage of plan assets mix		4.00%	4.00%
Other Mortgage and Asset Backed Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		$ 127	$ 86
Percentage of plan assets mix		1.00%	1.00%
Derivatives and Other, Net
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		$ (27)	$ 2
Percentage of plan assets mix		0.00%	0.00%
Common Collective Funds
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Fair value asset measurements		$ 3,691	$ 2,778
Percentage of plan assets mix		24.00%	21.00%
Alternative Investments Funds
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Fair value asset measurements		$ 2,725	$ 2,363
Percentage of plan assets mix		17.00%	18.00%
Money Market Funds and Other
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Fair value asset measurements		$ 1,293	$ 1,270
Percentage of plan assets mix		8.00%	9.00%
Level 1
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		$ 6,841	$ 5,902
Level 1 | Cash
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		197	57
Level 1 | Equity Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy	[1]	3,468	3,023
Level 1 | Mutual Funds
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		1,140	800
Level 1 | US Government Debt Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		2,042	2,019
Level 1 | Corporate Bond Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		0	0
Level 1 | Other Mortgage and Asset Backed Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		0	0
Level 1 | Derivatives and Other, Net
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		(6)	3
Level 2
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		1,090	1,146
Level 2 | Cash
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		0	0
Level 2 | Equity Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy	[1]	0	0
Level 2 | Mutual Funds
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		0	0
Level 2 | US Government Debt Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		404	488
Level 2 | Corporate Bond Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		580	573
Level 2 | Other Mortgage and Asset Backed Securities
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		127	86
Level 2 | Derivatives and Other, Net
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Investments in the Fair Value Hierarchy		$ (21)	$ (1)

[1] Includes 2.9 million shares of Company common stock valued at $373 million (2% of total plan assets) and 2.8 million shares valued at $332 million (2% of total plan assets) at September 28, 2019 and September 29, 2018, respectively.