Employee Benefit Plans - Net Periodic Benefit (Income) Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Postemployment Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net service cost	$ 31	$ 43	$ 34
Interest cost	3	3	2
Amortization of prior service cost	(2)	(5)	(6)
Actuarial loss (gain)	(3)	(1)	(6)
Defined Benefit Plan Net Periodic Benefit Costs, Subtotal	29	40	24
Postretirement Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost	1	0	1
Amortization of prior service cost	(5)	(5)	(6)
Actuarial loss (gain)	0	1	2
Net periodic benefit cost	(4)	(4)	(3)
Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net service cost	7	7	8
Interest cost	85	81	91
Expected return on plan assets	(74)	(75)	(92)
Amortization of prior service cost	1	1	1
Actuarial loss (gain)	75	(45)	28
Net periodic benefit cost	94	(31)	36
U.S. Pension Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net service cost	0	0	0
Interest cost	66	61	71
Expected return on plan assets	(43)	(43)	(57)
Amortization of prior service cost	0	0	0
Actuarial loss (gain)	60	(29)	28
Net periodic benefit cost	83	(11)	42
International Pension Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net service cost	7	7	8
Interest cost	19	20	20
Expected return on plan assets	(31)	(32)	(35)
Amortization of prior service cost	1	1	1
Actuarial loss (gain)	15	(16)	0
Net periodic benefit cost	11	$ (20)	$ (6)
Voluntary lump sum payment [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Benefits Paid	130
Voluntary lump sum payment and single premium group annuity contract [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Actuarial loss (gain)	(25)
Single premium group annuity contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Benefits Paid	$ 190