Other Income (Expense) - MEC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	$ (17)	$ 88	$ 97
MEC
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	53	52	50
MEC | Non-service cost components of postretirement employee benefit plans
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	26	24	17
MEC | Corporate-owned life insurance income
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	21	16	24
MEC | Gains on disposition of assets
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	0	6	0
MEC | Interest income and other, net
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	$ 6	$ 6	$ 9