Pension Plans, Postretirement and Other Employee Benefits - Summary of Amount Recognized in Balance Sheets for Pension Plans and Postretirement Benefit Plan (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Noncurrent liabilities		$ (1,101)	$ (1,145)
Pension Plans | U.S.
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at December 31 of the previous year		1,320	1,302
Service cost		1	2
Interest cost		41	53	$ 21
Settlement		0	(67)
Administrative expenses/taxes paid		0	0
Plan amendments		1	0
Actuarial (gain)/loss		114	105
Other		0	0
Benefits paid		(94)	(75)
Participants’ contributions		0	0
Currency rate conversion and other		0	0
Currency rate conversion and other		0	0
Benefit obligation at December 31	$ 1,302	1,383	1,320	1,302
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance at December 31 of the previous year		1,062	995
Settlement		0	(67)
Net realized/unrealized gains (loss)		126	183
Administrative expenses/taxes paid		0	0
Employer contributions		51	26
Participants’ contributions		0	0
Benefits paid		(94)	(75)
Currency rate conversion and other		0	0
Other		0	0
Currency rate conversion and other		0	0
Ending Balance at December 31	995	1,145	1,062	995
Funded status of the plans		(238)	(258)
Noncurrent assets		0	0
Current liabilities		(2)	(4)
Noncurrent liabilities		(236)	(254)
Net amount recognized		(238)	(258)
Pension Plans | Non-U.S.
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at December 31 of the previous year		1,048	946
Service cost		25	24
Interest cost		18	24	15
Settlement		(17)	(5)
Administrative expenses/taxes paid		(5)	(4)
Plan amendments		0	0
Actuarial (gain)/loss		28	105
Other		2	0
Benefits paid		(44)	(44)
Participants’ contributions		1	1
Currency rate conversion and other		(66)	(1)
Currency rate conversion and other		66	1
Benefit obligation at December 31	946	1,122	1,048	946
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance at December 31 of the previous year		523	466
Settlement		(17)	(5)
Net realized/unrealized gains (loss)		47	55
Administrative expenses/taxes paid		(5)	(4)
Employer contributions		42	42
Participants’ contributions		1	1
Benefits paid		(44)	(44)
Currency rate conversion and other		(66)	(1)
Other		2	0
Currency rate conversion and other		22	12
Ending Balance at December 31	466	571	523	466
Funded status of the plans		(551)	(525)
Noncurrent assets		37	35
Current liabilities		(18)	(17)
Noncurrent liabilities		(570)	(543)
Net amount recognized		(551)	(525)
Other Postretirement Benefits Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at December 31 of the previous year		300	322
Service cost		0	1
Interest cost		9	13	8
Settlement		0	0
Administrative expenses/taxes paid		0	0
Plan amendments	(66)	(59)	(17)
Actuarial (gain)/loss		5	6
Other		0	0
Benefits paid		(18)	(26)
Participants’ contributions		0	1
Currency rate conversion and other		0	0
Currency rate conversion and other		0	0
Benefit obligation at December 31	322	237	300	322
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance at December 31 of the previous year		0	0
Settlement		0	0
Net realized/unrealized gains (loss)		0	0
Administrative expenses/taxes paid		0	0
Employer contributions		18	25
Participants’ contributions		0	1
Benefits paid		(18)	(26)
Currency rate conversion and other		0	0
Other		0	0
Currency rate conversion and other		0	0
Ending Balance at December 31	$ 0	0	0	$ 0
Funded status of the plans		(237)	(300)
Noncurrent assets		0	0
Current liabilities		(23)	(25)
Noncurrent liabilities		(214)	(275)
Net amount recognized		(237)	(300)
Postretirement liability		$ 81	$ 73