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Derivative financial instruments (Tables) | 12 Months Ended
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Dec. 31, 2018
Disclosure of derivative financial instruments [Abstract] |
Disclosure of detailed information about hedge derivatives financial instruments [text block] | The table below presents the composition of open transactions included in the hedge derivative financial instruments as of December 31, 2018:
|  |  |  |  | Quotations |  |  |  |
Period of settlement |  | MT |  |  | Fixed |  | Futures |  |  | Fair value |
|  |  |  |  |  |  |  |  |  | US$(000) |
January 2019 |  |  | 1,000 |  |  | 7,345 |  | 5,961 |  |  |  | 1,381 |
February 2019 |  |  | 1,000 |  |  | 7,352 |  | 5,968 |  |  |  | 1,378 |
|  |  | 2,000 |  |  |  |  |  |  |  |  | 2,759 |
The table below presents the composition of open transactions included in the hedge derivative financial instruments as of December 31, 2017:
|  |  |  |  | Quotations |  |  |
Period of settlement |  | MT |  |  | Fixed |  | Futures |  |  | Fair value |
|  |  |  |  |  |  |  |  |  | US$(000) |
January 2018 |  |  | 3,000 |  |  | 5,972 – 6,050 |  | 7,275 |  |  |  | (3,787 | )
February 2018 |  |  | 3,000 |  |  | 5,972 – 6,050 |  | 7,260 |  |  |  | (3,736 | )
March 2018 |  |  | 3,000 |  |  | 5,972 – 6,050 |  | 7,247 |  |  |  | (3,693 | )
April 2018 |  |  | 3,000 |  |  | 5,805 – 6,050 |  | 7,259 |  |  |  | (3,973 | )
May 2018 |  |  | 3,000 |  |  | 5,900 – 6,300 |  | 7,269 |  |  |  | (3,484 | )
June 2018 |  |  | 3,000 |  |  | 5,900 – 6,325 |  | 7,277 |  |  |  | (3,468 | )
July 2018 |  |  | 3,000 |  |  | 5,960 – 6,350 |  | 7,285 |  |  |  | (3,359 | )
August 2018 |  |  | 3,000 |  |  | 6,520 |  | 7,290 |  |  |  | (2,288 | )
September 2018 |  |  | 3,000 |  |  | 7,100 |  | 7,296 |  |  |  | (580 | )
October 2018 |  |  | 3,000 |  |  | 7,200 |  | 7,300 |  |  |  | (296 | )
November 2018 |  |  | 3,000 |  |  | 7,300 |  | 7,305 |  |  |  | (13 | )
December 2018 |  |  | 3,000 |  |  | 7,300 |  | 7,309 |  |  |  | (28 | )
|  |  | 36,000 |  |  |  |  |  |  |  |  | (28,705 | )

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- Definition The disclosure of detailed information about hedge derivatives financial instruments. + References No definition available. + Details
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