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Postretirement benefits Weighted Average Assumption used to determine the net periodic cost of benefit (Details) | 12 Months Ended
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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%

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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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- Definition Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(3) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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- Definition Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(2) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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