Pensions Benefit Plans and Other Postretirement Benefits - Projected and Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets (Details) - Pension Benefit Plans - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
U.S.
Projected Benefit Obligation Exceeds the Fair Value of Plan Assets
Projected benefit obligations	$ 1,505	$ 1,413
Accumulated benefit obligation	1,505	1,412
Fair value of plan assets	1,215	1,094
Accumulated Benefit Obligations Exceeds the Fair Value of Plan Assets
Projected benefit obligations	1,505	1,413
Accumulated benefit obligation	1,505	1,412
Fair value of plan assets	1,215	1,094
Non-U.S.
Projected Benefit Obligation Exceeds the Fair Value of Plan Assets
Projected benefit obligations	952	815
Accumulated benefit obligation	927	793
Fair value of plan assets	706	591
Accumulated Benefit Obligations Exceeds the Fair Value of Plan Assets
Projected benefit obligations	952	815
Accumulated benefit obligation	927	793
Fair value of plan assets	$ 706	$ 591