v3.25.4
Income from operations - Audit and audit-related fees (Detail) - EUR (€)
€ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Income from operations [Line Items]    
Auditor's remuneration for audit services € 12.7 € 15.0
Audit-related fees 1.3 2.2
Auditor's remuneration for tax services 0.0 0.0
Auditor's remuneration for other services 0.0 0.0
Auditor's remuneration 14.0 17.2
EY NL    
Income from operations [Line Items]    
Auditor's remuneration for audit services   9.5
Audit-related fees   1.9
Auditor's remuneration   11.4
EY Network    
Income from operations [Line Items]    
Auditor's remuneration for audit services   5.5
Audit-related fees   0.3
Auditor's remuneration   5.8
PwC NL    
Income from operations [Line Items]    
Auditor's remuneration for audit services 6.5  
Audit-related fees 1.3  
Auditor's remuneration for tax services 0.0  
Auditor's remuneration for other services 0.0  
Auditor's remuneration 7.8  
PwC Network    
Income from operations [Line Items]    
Auditor's remuneration for audit services 6.2  
Audit-related fees 0.0  
Auditor's remuneration for tax services 0.0  
Auditor's remuneration for other services 0.0  
Auditor's remuneration 6.2  
Consolidated financial statements    
Income from operations [Line Items]    
Auditor's remuneration for audit services 9.4 12.5
Consolidated financial statements | EY NL    
Income from operations [Line Items]    
Auditor's remuneration for audit services   9.5
Consolidated financial statements | EY Network    
Income from operations [Line Items]    
Auditor's remuneration for audit services   3.0
Consolidated financial statements | PwC NL    
Income from operations [Line Items]    
Auditor's remuneration for audit services 6.5  
Consolidated financial statements | PwC Network    
Income from operations [Line Items]    
Auditor's remuneration for audit services 2.9  
Statutory financial statement    
Income from operations [Line Items]    
Auditor's remuneration for audit services 3.3 2.5
Statutory financial statement | EY NL    
Income from operations [Line Items]    
Auditor's remuneration for audit services   0.0
Statutory financial statement | EY Network    
Income from operations [Line Items]    
Auditor's remuneration for audit services   2.5
Statutory financial statement | PwC NL    
Income from operations [Line Items]    
Auditor's remuneration for audit services 0.0  
Statutory financial statement | PwC Network    
Income from operations [Line Items]    
Auditor's remuneration for audit services 3.3  
Sustainability assurance    
Income from operations [Line Items]    
Audit-related fees 1.3 1.6
Sustainability assurance | EY NL    
Income from operations [Line Items]    
Audit-related fees   1.6
Sustainability assurance | EY Network    
Income from operations [Line Items]    
Audit-related fees   0.0
Sustainability assurance | PwC NL    
Income from operations [Line Items]    
Audit-related fees 1.3  
Sustainability assurance | PwC Network    
Income from operations [Line Items]    
Audit-related fees 0.0  
Other services    
Income from operations [Line Items]    
Audit-related fees 0.1 0.6
Other services | EY NL    
Income from operations [Line Items]    
Audit-related fees   0.3
Other services | EY Network    
Income from operations [Line Items]    
Audit-related fees   € 0.3
Other services | PwC NL    
Income from operations [Line Items]    
Audit-related fees 0.1  
Other services | PwC Network    
Income from operations [Line Items]    
Audit-related fees € 0.0