Pension and Other Postretirement Benefits - Schedule of Amounts Reclassified from Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2025	Sep. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Other pension and postretirement	$ (5)			$ (523)			$ (9)	$ (547)
Income before taxes and equity in net earnings of affiliates	322			(177)			887	222
Provision for income taxes	(84)			39			(208)	(55)
Net income (loss)	239	$ 216	$ 227	(132)	$ 207	$ 93	682	168
Reclassification out of Accumulated Other Comprehensive Income | Defined benefit plans adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income before taxes and equity in net earnings of affiliates	3			525			9	550
Provision for income taxes	0			(129)			(2)	(134)
Net income (loss)	3			396			7	416
Reclassification out of Accumulated Other Comprehensive Income | Actuarial losses
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Other pension and postretirement	3			8			9	33
Reclassification out of Accumulated Other Comprehensive Income | Settlement loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Other pension and postretirement	$ 0			$ 517			$ 0	$ 517