Pension and Postretirement Benefit Plans (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Pension Plan [Member] | U.S. [Member] | Qualified [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions from our general assets for the six months ended June 30, 2019	$ 5
Expected contributions from our general assets during 2019	11	[1]
Pension Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions from our general assets for the six months ended June 30, 2019	130
Expected contributions from our general assets during 2019	191	[1]
Supplemental Employee Retirement Plan [Member] | U.S. [Member] | Non-Qualified [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions from our general assets for the six months ended June 30, 2019	99
Expected contributions from our general assets during 2019	197	[1]
Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions from our general assets for the six months ended June 30, 2019	67
Expected contributions from our general assets during 2019	$ 147	[1]

[1] Contributions expected to be made for 2019 are inclusive of amounts contributed during the six months ended June 30, 2019. 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.