Pension, Savings and Other Postretirement Benefit Plans - Defined Benefit Pension Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Type [Extensible List]	Pension Plan	Pension Plan	Pension Plan	Pension Plan
Service cost	$ 3	$ 1	$ 6	$ 3
Interest cost	26	32	68	97
Expected return on plan assets	(54)	(48)	(142)	(145)
Amortization of net losses	26	27	80	82
Net periodic pension cost	1	12	12	37
Net curtailments/settlements/termination benefits	11	18	30	25
Total defined benefit pension cost	$ 12	$ 30	$ 42	$ 62
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Type [Extensible List]	Pension Plan	Pension Plan	Pension Plan	Pension Plan
Service cost	$ 7	$ 8	$ 22	$ 22
Interest cost	13	14	35	42
Expected return on plan assets	(13)	(13)	(35)	(40)
Amortization of prior service cost	0	0	1	1
Amortization of net losses	8	9	25	28
Net periodic pension cost	15	18	48	53
Net curtailments/settlements/termination benefits	0	0	0	1
Total defined benefit pension cost	$ 15	$ 18	$ 48	$ 54