Other Expenses (Income), Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other Income and Expenses [Abstract]
Non-service costs — Pension and OPEB	$ 13	$ 20	$ 49	$ 59
Foreign currency losses, net	2	5	2	13
Interest income	(1)	0	(1)	(4)
Other, net	1	2	2	1
Nonoperating Income (Expense)	$ 15	$ 27	$ 52	$ 69