Postretirement benefits Schedule of Benefit Obligation in Excess of FV (Details) - Pension Plan [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	$ 3,967	$ 3,569
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets	3,739	3,301
Net Funded Status With PBO in Excess Of Plan Assets	(228)	(268)
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation	3,967	3,569
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets	3,739	3,301
Non - U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	629	236
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets	568	175
Net Funded Status With PBO in Excess Of Plan Assets	(61)	(61)
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation	593	173
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets	$ 565	$ 140