v3.26.1
Insurance Net Investment Result - Summary of Interest Income From Instruments Measured at Fair Value Through Profit or Loss (Detail) - EUR (€)
€ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL € 217 € 186 € 89
Non Derivative Assets [Member] | Applying the fair value option [member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 74 65 89
Non Derivative Assets [Member] | Failing the SPPI criteria [member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 15 13  
Income Or Loss From Insurance And Investment Contracts [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 615 637 737
Income Or Loss From Insurance And Investment Contracts [Member] | Insurance Contracts With Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 234 197 231
Income Or Loss From Insurance And Investment Contracts [Member] | Insurance Contracts Without Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 248 308 369
Income Or Loss From Insurance And Investment Contracts [Member] | Investment Contracts With Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 133 132 137
Income Or Loss From Insurance And Investment Contracts [Member] | Derivatives [member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL (4)    
Income Or Loss From Insurance And Investment Contracts [Member] | Derivatives [member] | Insurance Contracts With Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 0    
Income Or Loss From Insurance And Investment Contracts [Member] | Derivatives [member] | Insurance Contracts Without Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL (4)    
Income Or Loss From Insurance And Investment Contracts [Member] | Derivatives [member] | Investment Contracts With Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 0    
Income Or Loss From Insurance And Investment Contracts [Member] | Non Derivative Assets [Member] | Applying the fair value option [member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 357 340 422
Income Or Loss From Insurance And Investment Contracts [Member] | Non Derivative Assets [Member] | Applying the fair value option [member] | Insurance Contracts With Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 234 197 231
Income Or Loss From Insurance And Investment Contracts [Member] | Non Derivative Assets [Member] | Applying the fair value option [member] | Insurance Contracts Without Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL (10) 11 54
Income Or Loss From Insurance And Investment Contracts [Member] | Non Derivative Assets [Member] | Applying the fair value option [member] | Investment Contracts With Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 133 132 137
Income Or Loss From Insurance And Investment Contracts [Member] | Non Derivative Assets [Member] | Failing the SPPI criteria [member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 258 301 315
Income Or Loss From Insurance And Investment Contracts [Member] | Non Derivative Assets [Member] | Failing the SPPI criteria [member] | Insurance Contracts With Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 0    
Income Or Loss From Insurance And Investment Contracts [Member] | Non Derivative Assets [Member] | Failing the SPPI criteria [member] | Insurance Contracts Without Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL 258 € 301 € 315
Income Or Loss From Insurance And Investment Contracts [Member] | Non Derivative Assets [Member] | Failing the SPPI criteria [member] | Investment Contracts With Direct Participating Features [Member]      
Interest income from instruments measured at FVPL      
Interest income from instruments measured at FVPL € 0