Number of quarterly installments of vesting of share-based compensation awards.

No definition available.

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

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- Definition

Agreed-upon price for the exchange of the underlying asset relating to the share-based payment award.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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- Definition

Percentage of vesting of award under share-based payment arrangement.

+ References

+ Details

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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
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-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
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-Topic 505
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-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

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Stock-based compensation - 2018 Stock Option and Grant Plan (Details)	12 Months Ended
	Dec. 31, 2019 installment shares	Dec. 31, 2018 € / shares shares	Dec. 31, 2017 shares
Stock-based compensation
Issuance of common stock upon exercise of stock options (in shares)	157,636		0
Number of shares granted to US employee	1,661,200
Options outstanding	2,999,284	1,606,325
2018 Stock Option and Grant Plan
Stock-based compensation
Options outstanding	1,357,764
Vesting period	4 years
2018 Stock Option and Grant Plan \| Vesting upon first anniversary
Stock-based compensation
Percentage of options vesting	25.00%
2018 Stock Option and Grant Plan \| Vesting in equal quarterly installments
Stock-based compensation
Percentage of options vesting	75.00%
Number of quarterly installments for vesting \| installment	12
2016 Stock Option Plan
Stock-based compensation
Percentage of share price with fair market value	100.00%
2016 Stock Option Plan \| Exercise price 0.09 euros
Stock-based compensation
Exercise price for options granted as a replacement \| € / shares		€ 0.09
Number of shares granted to US employee		23,286
2016 Stock Option Plan \| Exercise price $2.93
Stock-based compensation
Number of shares granted to US employee		2.93