Provisions for pensions and similar obligations (Details 18)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension
Actuarial Assumptions Adopted in Calculations
Nominal Discount Rate for Actuarial Obligation	9.10%	9.50%	10.90%
Rate Calculation of Interest Under Assets to the Next Year	9.10%	9.50%	10.90%
Estimated Long-term Inflation Rate	4.00%	4.00%	4.50%
Estimated Salary Increase Rate	5.00%	5.00%	5.00%
Mortality tables	AT2000	AT2000	AT2000
Health
Actuarial Assumptions Adopted in Calculations
Nominal Discount Rate for Actuarial Obligation	9.30%	9.70%	10.80%
Rate Calculation of Interest Under Assets to the Next Year	9.30%	9.70%	10.80%
Estimated Long-term Inflation Rate	4.00%	4.00%	4.50%
Estimated Salary Increase Rate	5.00%	5.00%	5.00%
Mortality tables	AT2000	AT2000	AT2000

Actuarial Assumptions Adopted in Calculations

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- Definition

Mortality tables

+ References

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- Definition

The discount rate used as the significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit obligation, at present value; Actuarial assumptions [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2017-01-01
-Paragraph 144
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_144&doctype=Standard
-URIDate 2017-03-09

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- Definition

The expected rate of inflation that is used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [member]; Defined benefit obligation, at present value; Actuarial assumptions [member]]

+ References

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- Definition

The expected rate of salary increases used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [member]; Defined benefit obligation, at present value; Actuarial assumptions [member]]

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- Definition

Any other material assumption used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Actuarial assumptions [member]; Defined benefit obligation, at present value]

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