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Related party transactions (Tables) | 12 Months Ended
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Dec. 31, 2016
Related Party Transactions [Abstract] |
Schedule of related party transactions | A summary of the aforementioned significant related party transactions for the years ended December 31, 2016, 2015 and 2014 is as follows:
| Year Ended December 31,
| 2016 | 2015 | 2014
Net sales to Glencore | $ | 1,178,631 |  | $ | 1,867,711 |  | $ | 1,262,101 |
Purchases from Glencore | 231,850 |  | 393,158 |  | 285,167 |
Purchases from BHH | 10,127 |  | 46,592 |  | 47,804 |

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- Definition Tabular disclosure of related party transactions. Examples of related party transactions include, but are not limited to, transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners and (d) affiliates. + References No definition available. + Details
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