v3.26.1
Schedule I - Summary of Investments Other than Investments in Related Parties (Detail)
€ in Millions, $ in Millions
Dec. 31, 2025
EUR (€)
Dec. 31, 2024
EUR (€)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Disclosure of investments [Line Items]        
Financial assets € 69,293 € 76,020    
Investments in real estate 479 € 514 $ 514 $ 488
Cost [member]        
Disclosure of investments [Line Items]        
Financial assets 72,364      
Cost [member] | Shares [member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 233      
Fair value through other comprehensive income 6      
Cost [member] | Bonds [member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 2,382      
Amortized cost, Bonds 36      
Cost [member] | Bonds [member] | Financial assets at fair value through other comprehensive income, category [member]        
Disclosure of investments [Line Items]        
Financial assets 53,201      
Cost [member] | Bonds [member] | Asset backed [member]        
Disclosure of investments [Line Items]        
Financial assets 5,627      
Cost [member] | Bonds [member] | US government [member]        
Disclosure of investments [Line Items]        
Financial assets 6,193      
Cost [member] | Bonds [member] | Dutch government [member]        
Disclosure of investments [Line Items]        
Financial assets 2      
Cost [member] | Bonds [member] | Other government [member]        
Disclosure of investments [Line Items]        
Financial assets 1,020      
Cost [member] | Bonds [member] | Mortgage backed [member]        
Disclosure of investments [Line Items]        
Financial assets 3,031      
Cost [member] | Bonds [member] | Corporate [member]        
Disclosure of investments [Line Items]        
Financial assets 34,985      
Cost [member] | Bonds [member] | Money market investments [member]        
Disclosure of investments [Line Items]        
Financial assets 2,309      
Cost [member] | Bonds [member] | Other [member]        
Disclosure of investments [Line Items]        
Financial assets 35      
Cost [member] | Other investments [member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 6,698      
Cost [member] | Deposits with financial institutions [member]        
Disclosure of investments [Line Items]        
Amortized cost, Deposits 11      
Cost [member] | Loans [Member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 82      
Amortized cost, Loans 9,672      
Cost [member] | Real estate [member]        
Disclosure of investments [Line Items]        
Investments in real estate 42      
Fair value [member]        
Disclosure of investments [Line Items]        
Financial assets 68,120      
Fair value [member] | Shares [member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 263      
Fair value through other comprehensive income 10      
Fair value [member] | Bonds [member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 2,438      
Amortized cost, Bonds 36      
Fair value [member] | Bonds [member] | Financial assets at fair value through other comprehensive income, category [member]        
Disclosure of investments [Line Items]        
Financial assets 49,747      
Fair value [member] | Bonds [member] | Asset backed [member]        
Disclosure of investments [Line Items]        
Financial assets 5,545      
Fair value [member] | Bonds [member] | US government [member]        
Disclosure of investments [Line Items]        
Financial assets 5,061      
Fair value [member] | Bonds [member] | Dutch government [member]        
Disclosure of investments [Line Items]        
Financial assets 2      
Fair value [member] | Bonds [member] | Other government [member]        
Disclosure of investments [Line Items]        
Financial assets 948      
Fair value [member] | Bonds [member] | Mortgage backed [member]        
Disclosure of investments [Line Items]        
Financial assets 2,976      
Fair value [member] | Bonds [member] | Corporate [member]        
Disclosure of investments [Line Items]        
Financial assets 32,878      
Fair value [member] | Bonds [member] | Money market investments [member]        
Disclosure of investments [Line Items]        
Financial assets 2,308      
Fair value [member] | Bonds [member] | Other [member]        
Disclosure of investments [Line Items]        
Financial assets 28      
Fair value [member] | Other investments [member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 6,589      
Fair value [member] | Deposits with financial institutions [member]        
Disclosure of investments [Line Items]        
Amortized cost, Deposits 11      
Fair value [member] | Loans [Member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 82      
Amortized cost, Loans 8,902      
Fair value [member] | Real estate [member]        
Disclosure of investments [Line Items]        
Investments in real estate 42      
Book value [member]        
Disclosure of investments [Line Items]        
Financial assets 68,890      
Book value [member] | Shares [member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 263      
Fair value through other comprehensive income 10      
Book value [member] | Bonds [member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 2,438      
Amortized cost, Bonds 36      
Book value [member] | Bonds [member] | Financial assets at fair value through other comprehensive income, category [member]        
Disclosure of investments [Line Items]        
Financial assets 49,747      
Book value [member] | Bonds [member] | Asset backed [member]        
Disclosure of investments [Line Items]        
Financial assets 5,545      
Book value [member] | Bonds [member] | US government [member]        
Disclosure of investments [Line Items]        
Financial assets 5,061      
Book value [member] | Bonds [member] | Dutch government [member]        
Disclosure of investments [Line Items]        
Financial assets 2      
Book value [member] | Bonds [member] | Other government [member]        
Disclosure of investments [Line Items]        
Financial assets 948      
Book value [member] | Bonds [member] | Mortgage backed [member]        
Disclosure of investments [Line Items]        
Financial assets 2,976      
Book value [member] | Bonds [member] | Corporate [member]        
Disclosure of investments [Line Items]        
Financial assets 32,878      
Book value [member] | Bonds [member] | Money market investments [member]        
Disclosure of investments [Line Items]        
Financial assets 2,308      
Book value [member] | Bonds [member] | Other [member]        
Disclosure of investments [Line Items]        
Financial assets 28      
Book value [member] | Other investments [member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 6,589      
Book value [member] | Deposits with financial institutions [member]        
Disclosure of investments [Line Items]        
Amortized cost, Deposits 11      
Book value [member] | Loans [Member]        
Disclosure of investments [Line Items]        
Fair value through profit or loss 82      
Amortized cost, Loans 9,672      
Book value [member] | Real estate [member]        
Disclosure of investments [Line Items]        
Investments in real estate € 42