Pension, Savings and Other Postretirement Benefit Plans - Defined Benefit Pension Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 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	$ 2	$ 1	$ 3	$ 2
Interest cost	22	32	42	65
Expected return on plan assets	(46)	(48)	(88)	(97)
Amortization of net losses	26	28	54	55
Net periodic pension cost	4	13	11	25
Net curtailments/settlements/termination benefits	19	6	19	7
Total defined benefit pension cost	$ 23	$ 19	$ 30	$ 32
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	$ 8	$ 7	$ 15	$ 14
Interest cost	11	14	22	28
Expected return on plan assets	(12)	(13)	(22)	(27)
Amortization of prior service cost	1	0	1	1
Amortization of net losses	9	9	17	19
Net periodic pension cost	17	17	33	35
Net curtailments/settlements/termination benefits	0	0	0	1
Total defined benefit pension cost	$ 17	$ 17	$ 33	$ 36