Employee Benefit Plans - Change in Benefit Obligation and Plan Assets, Funded Status, Amounts Recognized in Balance Sheet, and ABO in Excess of Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized in the Consolidated Balance Sheets
Noncurrent assets	$ 178	$ 140
Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation as of January 1	2,855	3,223
Net service cost	7	7	$ 8
Interest cost	85	81	91
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	4
Actuarial loss	341	(232)
Benefits paid	(180)	(185)
Plan participant contributions	1	1
Currency translation adjustments	19	(44)
Benefit obligation as of December 31	3,128	2,855	3,223
Accumulated benefit obligation as of December 31	3,117	2,843
Amounts recognized in the Consolidated Balance Sheets
Defined Benefit Plan, Benefit Obligation	(693)	(633)
Noncurrent assets	178	140
Current liabilities	(13)	(14)
Noncurrent liabilities	(858)	(759)
Net amounts recognized	(693)	(633)
Prior service cost	20	21
Total	20	21
Amounts recognized in the accumulated other comprehensive loss
Pension plans with accumulated benefit obligations in excess of plan assets, projected benefit obligation	2,222	2,016
Pension plans with accumulated benefit obligations in excess of plan assets, accumulated benefit obligation	2,217	2,012
Pension plans with accumulated benefit obligations in excess of plan assets, fair value of plan assets	1,380	1,271
U.S. Pension Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation as of January 1	1,763	1,950
Net service cost	0	0	0
Interest cost	66	61	71
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	0
Actuarial loss	229	(149)
Benefits paid	(104)	(99)
Plan participant contributions	0	0
Currency translation adjustments	0	0
Benefit obligation as of December 31	1,954	1,763	1,950
Accumulated benefit obligation as of December 31	1,954	1,763
Amounts recognized in the Consolidated Balance Sheets
Defined Benefit Plan, Benefit Obligation	(577)	(494)
Noncurrent assets	0	0
Current liabilities	0	0
Noncurrent liabilities	(577)	(494)
Net amounts recognized	(577)	(494)
Prior service cost	0	0
Total	0	0
Foreign Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation as of January 1	1,092	1,273
Net service cost	7	7	8
Interest cost	19	20	20
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	4
Actuarial loss	112	(83)
Benefits paid	(76)	(86)
Plan participant contributions	1	1
Currency translation adjustments	19	(44)
Benefit obligation as of December 31	1,174	1,092	1,273
Accumulated benefit obligation as of December 31	1,163	1,080
Amounts recognized in the Consolidated Balance Sheets
Defined Benefit Plan, Benefit Obligation	(116)	(139)
Noncurrent assets	178	140
Current liabilities	(13)	(14)
Noncurrent liabilities	(281)	(265)
Net amounts recognized	(116)	(139)
Prior service cost	20	21
Total	20	21
Postretirement Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation as of January 1	18	21
Interest cost	1	0	1
Actuarial loss	0	(3)
Benefits paid	(2)	(1)
Plan participant contributions	0	1
Benefit obligation as of December 31	17	18	21
Amounts recognized in the Consolidated Balance Sheets
Defined Benefit Plan, Benefit Obligation	(17)	(18)
Current liabilities	(2)	(2)
Noncurrent liabilities	(15)	(16)
Net amounts recognized	(17)	(18)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	7	7
Prior service cost	(3)	(8)
Total	4	(1)
Postemployment Benefit Plans Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation as of January 1	139	142
Net service cost	31	43	34
Interest cost	3	3	2
Actuarial loss	(11)	(3)
Benefits paid	(35)	(40)
Currency translation adjustments	(1)	(6)
Benefit obligation as of December 31	126	139	$ 142
Amounts recognized in the Consolidated Balance Sheets
Defined Benefit Plan, Benefit Obligation	(126)	(139)
Current liabilities	(30)	(37)
Noncurrent liabilities	(96)	(102)
Net amounts recognized	(126)	(139)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	(38)	(28)
Prior service cost	(6)	(6)
Total	$ (44)	$ (34)