Pension and Postretirement Benefit Plans (Detail) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
		Mar. 29, 2020	Dec. 31, 2020
Pension Plan [Member] | U.S. [Member] | Qualified [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions from our general assets for the three months ended March 29, 2020		$ 3
Expected contributions from our general assets during 2020	[1]	1,276
Pension Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions from our general assets for the three months ended March 29, 2020		46
Expected contributions from our general assets during 2020	[1]	186
Supplemental Employee Retirement Plan [Member] | U.S. [Member] | Non-Qualified [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions from our general assets for the three months ended March 29, 2020		132
Expected contributions from our general assets during 2020	[1]	228
Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions from our general assets for the three months ended March 29, 2020		45
Expected contributions from our general assets during 2020	[1]	$ 155
Forecast [Member] | Pension Plan [Member] | U.S. [Member] | Qualified [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions from our general assets for the three months ended March 29, 2020			$ 1,250

[1] Contributions expected to be made for 2020 are inclusive of amounts contributed during the three months ended March 29, 2020. The U.S. supplemental (non-qualified) pension plan, international pension plan and the postretirement plan contributions from our general assets include direct employer benefit payments. For the U.S. qualified plans, we plan to make a $1.25 billion voluntary contribution in the second half of 2020.