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Summary of Significant Accounting Policies (Tables) | 12 Months Ended
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Dec. 31, 2017
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Disclosure of Foreign Exchange Rates | The following table summarizes the main exchange rates used for the preparation of the Consolidated Financial Statements :
Foreign exchange rate for 1 Euro |  |  |  | Year ended December 31, 2017 |  |  | Year ended December 31, 2016 |  |  | Year ended December 31, 2015 |
|  |  | Average rate |  |  | Closing rate |  |  | Average rate |  |  | Closing rate |  |  | Average rate |  |  | Closing rate |
U.S. Dollars |  | USD |  |  | 1.1273 |  |  |  | 1.1993 |  |  |  | 1.1063 |  |  |  | 1.0541 |  |  |  | 1.1089 |  |  |  | 1.0887 |
Swiss Francs |  | CHF |  |  | 1.1103 |  |  |  | 1.1702 |  |  |  | 1.0901 |  |  |  | 1.0739 |  |  |  | 1.0669 |  |  |  | 1.0835 |
Czech Koruna |  | CZK |  |  | 26.3151 |  |  |  | 25.5349 |  |  |  | 27.0342 |  |  |  | 27.0210 |  |  |  | 27.2762 |  |  |  | 27.0226 |

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- Definition The entire disclosure for the effect of changes in foreign exchange rates. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 21 -IssueDate 2017-01-01 -Section Disclosure -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=21&date=2017-03-01&anchor=sect_Disclosure&doctype=Standard -URIDate 2017-03-09 + Details
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