Defined Benefit Postretirement Plans and Defined Contribution Plan - Obligations and Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Divestiture	$ 0	$ 0
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation	343	320
Change in benefit obligations:
Benefit obligations at January 1	326	384
Service cost	19	18
Interest cost	12	12
Plan amendment	0	0
Actuarial loss	48	(20)
Foreign currency exchange rate changes	0	0
Settlements paid	(45)	(62)
Benefits paid	(6)	(6)
Benefit obligations at December 31	354	326
Change in fair value of plan assets:
Fair value of plan assets at January 1	203	216
Actual return on plan assets	44	(6)
Employer contributions	40	61
Foreign currency exchange rate changes	0	0
Settlements paid	(45)	(62)
Benefits paid	(6)	(6)
Fair value of plan assets at December 31	236	203
Funded status of plans at December 31
Funded status of plans at December 31	(118)	(123)
Amounts recognized in the consolidated balance sheets:
Noncurrent assets	0	0
Current liabilities	(6)	(5)
Noncurrent liabilities	(112)	(118)
Accrued benefit cost	(118)	(123)
Pretax amounts in accumulated other comprehensive loss:
Net loss	85	90
Prior service cost	(29)	(36)
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Divestiture	666	0
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation	0	511
Change in benefit obligations:
Benefit obligations at January 1	511	599
Service cost	0	0
Interest cost	8	14
Plan amendment	0	3
Defined Benefit Plan, Benefit Obligation, Divestiture	(549)
Actuarial loss	36	38
Foreign currency exchange rate changes	6	(29)
Settlements paid	0	23
Benefits paid	(12)	(15)
Benefit obligations at December 31	0	511
Change in fair value of plan assets:
Fair value of plan assets at January 1	594	670
Actual return on plan assets	68	(21)
Employer contributions	8	17
Foreign currency exchange rate changes	8	(34)
Settlements paid	0	(23)
Benefits paid	(12)	(15)
Fair value of plan assets at December 31	0	594
Funded status of plans at December 31
Funded status of plans at December 31	0	83
Amounts recognized in the consolidated balance sheets:
Noncurrent assets	0	83
Current liabilities	0	0
Noncurrent liabilities	0	0
Accrued benefit cost	0	83
Pretax amounts in accumulated other comprehensive loss:
Net loss	0	(59)
Prior service cost	0	5
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Divestiture		0
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation	89	96
Change in benefit obligations:
Benefit obligations at January 1	96	221
Service cost	1	2
Interest cost	3	7
Plan amendment	0	(99)
Actuarial loss	9	(15)
Foreign currency exchange rate changes	0	0
Settlements paid	0	0
Benefits paid	(20)	(20)
Benefit obligations at December 31	89	96
Change in fair value of plan assets:
Fair value of plan assets at January 1	0	0
Actual return on plan assets	0	0
Employer contributions	20	20
Foreign currency exchange rate changes	0	0
Settlements paid	0	0
Benefits paid	(20)	(20)
Fair value of plan assets at December 31	0	0
Funded status of plans at December 31
Funded status of plans at December 31	(89)	(96)
Amounts recognized in the consolidated balance sheets:
Noncurrent assets	0	0
Current liabilities	(18)	(19)
Noncurrent liabilities	(71)	(77)
Accrued benefit cost	(89)	(96)
Pretax amounts in accumulated other comprehensive loss:
Net loss	23	14
Prior service cost	$ (129)	$ (147)