Income Tax (Details) - EUR (€) € in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax
Loss before tax	€ (54,294)	€ (49,271)	€ (33,619)
Theoretical tax rate	25.00%	26.50%	28.00%
Tax benefit at theoretical rate	€ 13,574	€ 13,057	€ 9,413
Tax credits	1,432	1,078	2,143
Permanent differences	(305)	85	1,641
Other differences	(428)	(582)	(471)
Tax rate differences	55	(80)
Non recognition of deferred tax assets related to tax losses and temporary differences	(14,309)	(13,921)	(12,726)
Actual income tax benefit	20	(364)
Current taxes	(34)	€ (364)
Deferred taxes	€ (54)
Effective tax rate	0.06%	0.74%
Deferred tax assets	€ 0	€ 0	€ 0

The amount of profit (loss) for a period before deducting tax expense. [Refer: Profit (loss)]

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The applicable income tax rate.

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The tax expense (income) divided by the accounting profit. [Refer: Accounting profit]

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The amount of income taxes payable (recoverable) in respect of the taxable profit (tax loss) for a period.

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The amounts of income taxes recoverable in future periods in respect of: (a) deductible temporary differences; (b) the carryforward of unused tax losses; and (c) the carryforward of unused tax credits. [Refer: Temporary differences [member]; Unused tax credits [member]; Unused tax losses [member]]

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The amount of tax expense or income relating to changes in deferred tax liabilities and deferred tax assets, recognised in profit or loss. [Refer: Deferred tax assets; Deferred tax expense (income); Deferred tax liabilities]

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The aggregate amount included in the determination of profit (loss) for the period in respect of current tax and deferred tax. [Refer: Current tax expense (income); Deferred tax expense (income)]

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that the entity does not separately disclose in the same statement or note. [Refer: Accounting profit; Applicable tax rate]

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The amount of benefit arising from a previously unrecognised tax loss, tax credit or temporary difference of a prior period that is used to reduce current tax expense. [Refer: Temporary differences [member]; Unused tax losses [member]; Unused tax credits [member]]

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to foreign tax rates. [Refer: Accounting profit]

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The product of the accounting profit multiplied by the applicable tax rate(s). [Refer: Accounting profit; Applicable tax rate]

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The amount due to unrecognized deferred tax assets related to tax losses and temporary differences for reconciliation between accounting profit and tax expense income.

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The amount due to permanent differences for reconciliation between accounting profit and tax expense income.

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