v3.26.1
Fair Value - Analysis of Assets and Liabilities Recorded at Fair Value on Recurring Basis by Level of Fair Value Hierarchy (Detail) - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value € 59,574 € 65,375
Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 275,964 283,908
Liabilities carried at fair value 86,630 81,513
Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 49,757 54,715
Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 226,151 229,127
Shares [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 10 39
Shares [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 263 279
Debt securities [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 47,411 52,211
Debt securities [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 2,438 2,385
Money Markets and other short-term investment [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 2,308 2,435
Money Markets and other short-term investment [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 1,868 2,096
Other investments [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 28 31
Other investments [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 4,721 5,176
Loans [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 82 82
Derivatives [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 485 771
Real estate [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 42 57
Investments in real estate for policyholders [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 437 457
Investments - Policyholder Risk [Member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 215,814 217,824
Real estate held for own use (revalued amount) [Member] | Financial assets revalued amount [Member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 56 66
Investment contracts without DPF - Policyholder risk [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Liabilities carried at fair value 85,161 79,078
Derivatives [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Liabilities carried at fair value 1,469 2,435
Level I [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 98,158 107,738
Liabilities carried at fair value 50 53
Level I [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 6,272 7,592
Level I [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 91,886 100,146
Level I [member] | Shares [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 5 34
Level I [member] | Shares [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 179 163
Level I [member] | Debt securities [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 4,165 5,170
Level I [member] | Debt securities [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 253 308
Level I [member] | Money Markets and other short-term investment [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 2,102 2,388
Level I [member] | Money Markets and other short-term investment [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 1,708 1,961
Level I [member] | Other investments [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 18 1
Level I [member] | Derivatives [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 14 30
Level I [member] | Investments - Policyholder Risk [Member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 89,715 97,682
Level I [member] | Derivatives [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Liabilities carried at fair value 50 53
Level II [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 172,107 169,734
Liabilities carried at fair value 86,580 81,460
Level II [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 42,951 46,320
Level II [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 129,156 123,414
Level II [member] | Shares [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 30 30
Level II [member] | Debt securities [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 42,717 46,242
Level II [member] | Debt securities [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 2,075 1,970
Level II [member] | Money Markets and other short-term investment [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 207 47
Level II [member] | Money Markets and other short-term investment [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 160 135
Level II [member] | Other investments [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 27 31
Level II [member] | Other investments [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 716 718
Level II [member] | Derivatives [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 464 732
Level II [member] | Investments - Policyholder Risk [Member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 125,710 119,829
Level II [member] | Investment contracts without DPF - Policyholder risk [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Liabilities carried at fair value 85,161 79,078
Level II [member] | Derivatives [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Liabilities carried at fair value 1,419 2,382
Level III [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 5,699 6,436
Level III [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 533 799
Assets carried at fair value   803
Level III [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 5,109 5,567
Level III [member] | Shares [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 5 4
Level III [member] | Shares [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 54 86
Level III [member] | Debt securities [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 528 799
Level III [member] | Debt securities [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 110 107
Level III [member] | Other investments [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 4,765 5,530
Level III [member] | Other investments [member] | Fair value through other comprehensive income [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 1  
Level III [member] | Other investments [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 3,987 4,457
Level III [member] | Loans [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 82 82
Level III [member] | Derivatives [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 8 9
Level III [member] | Real estate [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 42 57
Level III [member] | Investments in real estate for policyholders [member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 437 457
Level III [member] | Investments - Policyholder Risk [Member] | Financial assets at fair value through profit or loss [member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value 389 312
Level III [member] | Real estate held for own use (revalued amount) [Member] | Financial assets revalued amount [Member] | Recurring fair value measurement [member]    
Disclosure of fair value measurement of assets and liabilities [line items]    
Assets carried at fair value € 56 € 66