Postretirement benefits (Narrative) (Details) - USD ($) $ in Millions		12 Months Ended
	Oct. 31, 2016	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Expenses recognized during period under the defined contributions plans		$ 214	$ 211	$ 171
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation		4,800	5,100
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		17
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		119	120	152
Actuarial Loss (gain)		(10)	1
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation		20	23
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		1
Defined Benefit Plan, Plan Amendment [Abstract]
(Increase) decrease in other comprehensive income, curtailment		0	0	0
Amortization of Prior Service Cost (Credit)		$ 26	83	84
Defined Benefit Plan, Equity Securities [Member] | Minimum
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage		55.00%
Defined Benefit Plan, Equity Securities [Member] | Maximum
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage		65.00%
UNITED STATES | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		$ 4,151	3,739	3,301
Actuarial Loss (gain)		(161)	441
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation		73	3,967
Defined Benefit Plan, Plan Amendment [Abstract]
(Increase) decrease in other comprehensive income, curtailment		0	0	0
Amortization of Prior Service Cost (Credit)		0	0	0
UNITED STATES | Postretirement Health Coverage [Member]
Defined Benefit Plan, Plan Amendment [Abstract]
Effect of Plan Amendment on Accumulated Benefit Obligation	$ 383
Amortization of Prior Service Cost (Credit)		26	79	79
UNITED STATES | Postretirement Health Coverage [Member] | Subject to Amortization [Member]
Defined Benefit Plan, Plan Amendment [Abstract]
Effect of Plan Amendment on Accumulated Benefit Obligation	$ 410
Non - U.S. | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		1,318	1,284	1,141
Actuarial Loss (gain)		(47)	135
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation		380	593
Defined Benefit Plan, Plan Amendment [Abstract]
(Increase) decrease in other comprehensive income, curtailment		0	(1)	(3)
Amortization of Prior Service Cost (Credit)		$ 0	$ 0	$ 0