Pension, Savings and Other Postretirement Benefit Plans - Defined Benefit Pension Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Type [Extensible List]	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember
Service cost	$ 1		$ 3	$ 2
Interest cost	32	$ 44	97	130
Expected return on plan assets	(48)	(56)	(145)	(167)
Amortization of net losses	27	28	82	84
Net periodic pension cost	12	16	37	49
Net curtailments/settlements/termination benefits	18	1	25	1
Total defined benefit pension cost	$ 30	$ 17	$ 62	$ 50
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Type [Extensible List]	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember
Service cost	$ 8	$ 6	$ 22	$ 20
Interest cost	14	17	42	52
Expected return on plan assets	(13)	(14)	(40)	(44)
Amortization of prior service cost			1	1
Amortization of net losses	9	8	28	22
Net periodic pension cost	18	17	53	51
Net curtailments/settlements/termination benefits			1
Total defined benefit pension cost	$ 18	$ 17	$ 54	$ 51