Other (Income) Expense - Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Income and Expenses [Abstract]
(Gain) loss on sale and revaluation of assets	$ (161)	$ 39	$ (43)
Pension settlement	0	0	117
Other (income) expense - net	(117)	(32)	27
Other Nonoperating Income (Expense)	$ (278)	$ 7	$ 101