Financial Assets and Liabilities - Liquidity Risk Management (Detail) - EUR (€) € in Thousands	Mar. 31, 2026	Dec. 31, 2025
Borrowings [abstract]
Royalty funding liabilities	€ 298,100
Borrowings (excluding lease liabilities)	1,013,430
Lease liabilities	194,024
Trade payables, accrued expenses and other liabilities	92,913
Total financial liabilities	1,280,059	€ 1,219,720
Total financial liabilities	1,300,367
Financial liabilities at amortised cost, class [member]
Borrowings [abstract]
Convertible senior notes	448,176	429,391
Royalty funding liabilities	298,052	290,871
Borrowings (excluding lease liabilities)	746,228
Lease liabilities	150,436	151,524
Trade payables, accrued expenses and other liabilities	92,913
Other liabilities (excluding indirect tax, and employee related payables)	14,325	€ 1,046
Total financial liabilities	989,577
Within 1 year [member]
Borrowings [abstract]
Borrowings (excluding lease liabilities)	55,863
Lease liabilities	21,474
Trade payables, accrued expenses and other liabilities	92,913
Total financial liabilities	170,250
Within 1 to 5 years [member]
Borrowings [abstract]
Borrowings (excluding lease liabilities)	833,037
Lease liabilities	82,273
Trade payables, accrued expenses and other liabilities	0
Total financial liabilities	915,310
After 5 years [member]
Borrowings [abstract]
Borrowings (excluding lease liabilities)	124,530
Lease liabilities	90,277
Trade payables, accrued expenses and other liabilities	0
Total financial liabilities	€ 214,807

Contractual undiscounted cashflow of financial liabilities.

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Convertible senior notes.

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- Definition

Royalty funding liabilities.

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No definition available.

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- Definition

The amount of outstanding funds that the entity is obligated to repay.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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The amount of liabilities that are: (a) a contractual obligation: (i) to deliver cash or another financial asset to another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially unfavourable to the entity; or (b) a contract that will, or may be, settled in the entity’s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to deliver a variable number of the entity’s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity’s own equity instruments. For this purpose, rights, options or warrants to acquire a fixed number of the entity’s own equity instruments for a fixed amount of any currency are equity instruments if the entity offers the rights, options or warrants pro rata to all of its existing owners of the same class of its own non-derivative equity instruments. Also, for those purposes the entity’s own equity instruments do not include puttable financial instruments that are classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity’s own equity instruments. As an exception, an instrument that meets the definition of a financial liability is classified as an equity instrument if it has all the features and meets the conditions in paragraphs 16A-16B or paragraphs 16C-16D of IAS 32. [Refer: Classes of financial instruments [domain]; Financial assets; Derivatives [member]]

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The amount of liabilities related to the entity's leases. Lease is a contract, or part of a contract, that conveys the right to use an underlying asset for a period of time in exchange for consideration.

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The amount of financial liabilities that the entity does not separately disclose in the same statement or note. [Refer: Financial liabilities]

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The amount of trade payables and other payables. [Refer: Trade payables; Other payables]

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