v3.25.2
Financial liabilities - Disclosure of the main data and assumptions, Heights convertible loan notes (Details) - Heights convertible notes, tranche A
€ in Thousands
Jun. 30, 2025
EUR (€)
€ / shares
shares
Dec. 31, 2024
EUR (€)
€ / shares
shares
Disclosure of financial liabilities [line items]    
Number of outstanding notes (in shares) | shares 350 350
Original principal amount | € € 35 € 35
Fair value of convertible notes | € € 16,481 € 20,017
Interest rate | Monte Carlo model    
Disclosure of financial liabilities [line items]    
Significant unobservable input, liabilities 0.06 0.06
Conversion price per share (in euro per share) | Monte Carlo model    
Disclosure of financial liabilities [line items]    
Significant unobservable input, liabilities 23.77 23.77
Ordinary share price (in euro per share) | Monte Carlo model    
Disclosure of financial liabilities [line items]    
Significant unobservable input, liabilities 6.64 6.76
Held to maturity scenario probability | Monte Carlo model    
Disclosure of financial liabilities [line items]    
Significant unobservable input, liabilities 0.75 0.75
Initial price limit (in euro per share) | Monte Carlo model    
Disclosure of financial liabilities [line items]    
Significant unobservable input, liabilities 14.43 14.43
Early redemption amount (put event) | Monte Carlo model    
Disclosure of financial liabilities [line items]    
Significant unobservable input, liabilities 1.20 1.20
Volatility | Monte Carlo model    
Disclosure of financial liabilities [line items]    
Significant unobservable input, liabilities 0.50 0.50
Credit spread | Monte Carlo model    
Disclosure of financial liabilities [line items]    
Significant unobservable input, liabilities 0.25 0.25
Risk-free rate | Monte Carlo model    
Disclosure of financial liabilities [line items]    
Significant unobservable input, liabilities 0.019 0.029