Postretirement benefits Weighted Average Assumption used to determine the net periodic cost of benefit (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Rate of Compensation Increase	4.00%	4.00%	4.00%
Expected Long-term Return on Assets	7.00%	7.00%	7.00%
Interest crediting rate, net periodic benefit costs	4.10%	4.10%	4.10%
Pension Plan [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate of Compensation Increase	3.46%	3.57%	3.33%
Expected Long-term Return on Assets	4.32%	4.23%	4.79%
Pension Plan [Member] | Interest Cost [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.27%	3.53%	3.59%
Pension Plan [Member] | Interest Cost [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.55%	2.61%	3.44%
Pension Plan [Member] | Service Cost [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.62%	4.20%	4.38%
Pension Plan [Member] | Service Cost [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.97%	3.55%	3.85%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected Long-term Return on Assets	2.59%	3.00%	6.34%
Other Postretirement Benefits Plan [Member] | Interest Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.62%	2.44%	4.02%
Other Postretirement Benefits Plan [Member] | Service Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.84%	2.84%	4.32%