Pension and Other Postretirement Benefit Plans - Accumulated and Projected Benefit Obligation in Excess of Plan Assets (Details) - Pension Benefits - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plans with a projected benefit obligation in excess of plan assets, projected benefit obligation	$ 9,517	$ 10,446
Pension plans with a projected benefit obligation in excess of plan assets, fair value of plan assets	9,057	9,804
Pension plans with an accumulated benefit obligation in excess of plan assets, accumulated benefit obligation	442	9,700
Pension plans with an accumulated benefit obligation in excess of plan assets, fair value of plan assets	0	9,186
International
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plans with a projected benefit obligation in excess of plan assets, projected benefit obligation	1,847	2,961
Pension plans with a projected benefit obligation in excess of plan assets, fair value of plan assets	1,435	2,462
Pension plans with an accumulated benefit obligation in excess of plan assets, accumulated benefit obligation	1,768	1,791
Pension plans with an accumulated benefit obligation in excess of plan assets, fair value of plan assets	$ 1,385	$ 1,336