Financial risk management - Summary of Undrawn Borrowing Facilities (Detail) - EUR (€) € in Thousands  | 
Jun. 30, 2022  | 
Dec. 31, 2021  | 
Dec. 31, 2020  | 
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| Later than one year [member] | Senior Debt [Member] | |||
| Disclosure of Detailed Information About Undrawn Borrowing Facilities [Line Items] | |||
| Expiring beyond one year—Senior debt | € 0 | € 0 | € 44,315 | 
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- Definition Disclosure of detailed information about undrawn borrowing facilities. No definition available. 
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- Definition The amount of undrawn borrowing facilities that may be available for future operating activities and to settle capital commitments. [Refer: Capital commitments] Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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