Other Income (Expense) - MEC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	$ 116	$ (7)	$ (17)
MEC
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	36	0	53
MEC | Corporate-owned life insurance income (loss)
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	23	(16)	21
MEC | Non-service cost components of postretirement employee benefit plans
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	8	9	26
MEC | Interest income and other, net
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	$ 5	$ 7	$ 6