Non-cash stock-based compensation - Summary of assumptions Vesting Details (Detail) - Equity awards [member] - € / shares	6 Months Ended	12 Months Ended
Jun. 30, 2023	Dec. 31, 2022
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted-Average fair values of stock options granted	€ 1.65	€ 1.31
Share entitlement per options	1	1
Vesting conditions	Performance or Service	Performance or Service
Vesting period	Graded	Graded
Bottom of Range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate	2.45%	0.00%
Exercise price	€ 1.74	€ 2.09
Grant date share fair value	€ 1.7	€ 1.91
Expected volatility	63.70%	58.70%
Expected term (in years)	6.03	6.03
Top of Range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate	2.75%	2.49%
Exercise price	€ 3.17	€ 7.22
Grant date share fair value	€ 3.09	€ 6.74
Expected volatility	64.40%	62.50%
Expected term (in years)	6.15	6.15

Description of expected terms of years share options granted.

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- Definition

Description of vesting conditions for share-based payment arrangement

+ References

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Fair value at measurement date share options granted per share.

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- Definition

Number of shares entitled per option.

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- Definition

The weighted average per share price used as input to the option pricing model to calculate the fair value of share options granted.

+ References

No definition available.

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- Definition

The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2023-01-01
-Paragraph 47
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The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

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- Definition

The description of the vesting requirements for a type of share-based payment arrangement that existed at any time during the period. An entity with substantially similar types of share-based payment arrangements may aggregate this information. [Refer: Share-based payment arrangements [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

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The exercise price of share options granted.

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