4. Stock Options (Details) - EUR (€) € / shares in Units, € in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Minimum
Weighted Average Exercise Price Outstanding, Beginning	€ 0.02	€ 0.02
Weighted Average Exercise Price Outstanding, Ending	0.02	0.02
Weighted Average Exercise Price Exercisable	0.02	0.02
Maximum
Weighted Average Exercise Price Outstanding, Beginning	0.19	3.50
Weighted Average Exercise Price Outstanding, Ending	0.19	0.19
Weighted Average Exercise Price Exercisable	€ 0.19	€ 0.19
Stock options
Number of Options Outstanding, Beginning	29,580,000	20,850,000
Number of Options Granted	0	8,850,000
Number of Options Exercised	0	0
Number of Options Expired/Forfeited	(480,000)	(120,000)
Number of Options Outstanding, Ending	29,100,000	29,580,000
Number of Options Exercisable	19,970,000	13,970,000
Weighted Average Exercise Price Outstanding, Beginning		€ 0.040
Weighted Average Exercise Price Granted	€ 0	0.023
Weighted Average Exercise Price Exercised	0	0
Weighted Average Exercise Price Expired/Forfeited	0.023	€ 0.023
Weighted Average Exercise Price Outstanding, Ending	0.0364
Weighted Average Exercise Price Exercisable	€ 0.0432
Weighted Average Remaining Contractual Life Outstanding	6 years 9 months 18 days
Weighted Average Remaining Contractual Life Exercisable	6 years 5 months 8 days
Aggregate Intrinsic Value Outstanding, Ending	€ 8,725
Aggregate Intrinsic Value Exercisable	€ 6,575

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ References

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Gross number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of fully vested and expected to vest options that are exercisable.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of fully vested and expected to vest options outstanding.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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