v3.26.1
Share-based payments - Summary of Fair Value Per Option at Each Grant/Measurements Date Using the Black-Scholes Formula (Detail)
Jun. 01, 2026
yr
shares
€ / shares
May 01, 2026
€ / shares
Apr. 01, 2026
€ / shares
Mar. 03, 2026
yr
shares
€ / shares
Mar. 01, 2026
€ / shares
Feb. 01, 2026
€ / shares
Jan. 01, 2026
€ / shares
Mar. 12, 2025
shares
yr
€ / shares
Disclosure Of Significant Unobservable Inputs Used In Fair Value Measurement Of Assets [Line Items]                
Exercise price € 25.02 € 25.12 € 25.42 € 23.05 € 24.03 € 22.83 € 23.63  
Key management personnel of entity or parent [member]                
Disclosure Of Significant Unobservable Inputs Used In Fair Value Measurement Of Assets [Line Items]                
Exercise price       24.11        
Stock options granted to board of directors [Member]                
Disclosure Of Significant Unobservable Inputs Used In Fair Value Measurement Of Assets [Line Items]                
Exercise price       € 24.11        
Black-Scholes formula [member] | Key management personnel of entity or parent [member]                
Disclosure Of Significant Unobservable Inputs Used In Fair Value Measurement Of Assets [Line Items]                
Number of options | shares [1] 60,000     575,000       555,000
Fair value of the options [1] € 20.71     € 19.45       € 12.19
Fair value of the ordinary shares [1] 25.93     24.11       14.71
Exercise price [1] € 25.93     € 24.11       € 14.74
Expected volatility (%) [1] 100.00%     100.00%       105.00%
Expected life (years) | yr [1] 5.8     6.1       6.1
Risk-free interest rate (%) [1] 4.30%     3.80%       4.30%
Expected dividend yield [1]       0.00%       0.00%
Black-Scholes formula [member] | Stock options granted to board of directors [Member]                
Disclosure Of Significant Unobservable Inputs Used In Fair Value Measurement Of Assets [Line Items]                
Number of options | shares [2]       82,500       75,000
Fair value of the options [2]       € 18.88       € 11.86
Fair value of the ordinary shares [2]       24.11       14.71
Exercise price [2]       € 24.11       € 14.74
Expected volatility (%) [2]       100.00%       105.00%
Expected life (years) | yr [2]       5.5       5.5
Risk-free interest rate (%) [2]       3.80%       4.30%
Expected dividend yield [2]       0.00%       0.00%
[1] Granted to members of key management
[2] Granted to the Board of Directors