Pension Plans, Postretirement and Other Employee Benefits - Projected Benefit Obligation Accumulated Benefit Obligation and Fair Value of Plan Assets for All Pension Plans (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	$ 1,383	$ 1,320
Accumulated benefit obligation	1,383	1,320
Fair value of plan assets	1,145	1,062
Non-U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	696	682
Accumulated benefit obligation	654	637
Fair value of plan assets	118	126
Pension Plans | U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	1,383	1,320
Fair value of plan assets	1,145	1,062
Pension Plans | Non-U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	743	712
Fair value of plan assets	155	151
Other Postretirement Benefits Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	237	300
Fair value of plan assets	$ 0	$ 0