Pensions and Other Postretirement Benefits (Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2022	Jun. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit pension plan, decrease for remeasurement due to Settlement		$ 309
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost/(income)	$ 8		$ (6)		$ 213	$ (19)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost/(income)	6		6		17	19
Mandatory Contribution
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to defined benefit pension plans	$ 1		$ 0		$ 3	$ 2
Scenario, Forecast | Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost/(income)				$ 220
Scenario, Forecast | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost/(income)				$ 25