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EMPLOYEE BENEFITS - Defined benefit pension plan - Assumptions used to calculate defined benefit plans (Details) | Dec. 31, 2017 | Dec. 31, 2016
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Brazilian Plans |  |
Summary of assumptions used to calculate the defined benefit plans |  |
Average discount rate | 9.84% | 10.87%
North American Plans |  |
Summary of assumptions used to calculate the defined benefit plans |  |
Rate of increase in compensation | 3.00% | 3.25%
North American Plans | Minimum |  |
Summary of assumptions used to calculate the defined benefit plans |  |
Average discount rate | 3.25% | 3.75%
North American Plans | Maximum |  |
Summary of assumptions used to calculate the defined benefit plans |  |
Average discount rate | 4.25% | 4.25%

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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 + Details
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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]] + 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 + Details
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