Pension, Other Postretirement Benefits and Savings Plans - Benefit Costs and Amounts Recognized in Other Comprehensive (Income) Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Postretirement Benefits
Benefits cost (credit):
Service cost	$ 2	$ 3	$ 4
Interest cost	11	12	13
Expected return on plan assets	0	0	(1)
Amortization of prior service cost (credit)	(9)	(8)	(29)
Amortization of net losses	3	4	6
Net periodic cost (credit)	7	11	(7)
Net curtailments/settlements/termination benefits	0	0	0
Total benefits cost (credit)	7	11	(7)
Recognized in other comprehensive (income) loss before tax and minority:
Prior service cost (credit) from plan amendments	0	(16)	3
Increase (decrease) in net actuarial losses	6	(14)	(15)
Amortization of prior service (cost) credit in net periodic cost	9	8	29
Amortization of net losses in net periodic cost	(3)	(5)	(6)
Immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	2	0	0
Total recognized in other comprehensive (income) loss before tax and minority	14	(27)	11
Total recognized in total benefits cost (credit) and other comprehensive (income) loss before tax and minority	21	(16)	4
United States | Pension Plan
Benefits cost (credit):
Service cost	3	4	4
Interest cost	173	157	160
Expected return on plan assets	(223)	(219)	(241)
Amortization of prior service cost (credit)	0	0	0
Amortization of net losses	112	112	111
Net periodic cost (credit)	65	54	34
Net curtailments/settlements/termination benefits	8	8	29
Total benefits cost (credit)	73	62	63
Recognized in other comprehensive (income) loss before tax and minority:
Prior service cost (credit) from plan amendments	0	0	0
Increase (decrease) in net actuarial losses	4	14	128
Amortization of prior service (cost) credit in net periodic cost	0	0	0
Amortization of net losses in net periodic cost	(112)	(112)	(111)
Immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	(5)	(11)	(29)
Total recognized in other comprehensive (income) loss before tax and minority	(113)	(109)	(12)
Total recognized in total benefits cost (credit) and other comprehensive (income) loss before tax and minority	(40)	(47)	51
United States | Other Postretirement Benefits
Benefits cost (credit):
Total benefits cost (credit)	3	4	(17)
Non-U.S. | Pension Plan
Benefits cost (credit):
Service cost	26	28	31
Interest cost	69	69	71
Expected return on plan assets	(59)	(70)	(80)
Amortization of prior service cost (credit)	2	0	0
Amortization of net losses	29	29	32
Net periodic cost (credit)	67	56	54
Net curtailments/settlements/termination benefits	3	13	3
Total benefits cost (credit)	70	69	57
Recognized in other comprehensive (income) loss before tax and minority:
Prior service cost (credit) from plan amendments	(2)	31	3
Increase (decrease) in net actuarial losses	201	(18)	25
Amortization of prior service (cost) credit in net periodic cost	(2)	0	0
Amortization of net losses in net periodic cost	(29)	(30)	(29)
Immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	(3)	(14)	(12)
Total recognized in other comprehensive (income) loss before tax and minority	165	(31)	(13)
Total recognized in total benefits cost (credit) and other comprehensive (income) loss before tax and minority	235	38	44
Non-U.S. | Other Postretirement Benefits
Benefits cost (credit):
Total benefits cost (credit)	$ 4	$ 7	$ 10