v3.26.1
(Re)Insurance contracts and investment contracts with discretionary participation features - Summary of Movement Schedules by Measurement Component (Detail) - EUR (€)
€ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets € 18    
Beginning balance 176,067    
Opening net balance 176,049    
Opening assets, Reinsurance 17,153    
Opening liabilities, Reinsurance 195    
Net opening balance, Investment contracts 21,281 € 22,332 € 22,332
Variable Fee Approach [Abstract]      
Closing net balance 137,391   176,049
Closing assets 16   18
Closing balance 137,407   176,067
Closing assets, Reinsurance 17,374   17,153
Closing liabilities, Reinsurance 201   195
Net closing balance, Investment contracts 20   21,281
Reinsurance contracts held [member]      
General Model [Abstract]      
Interest accreted to insurance contracts 339 [1] 280 [2]  
Revaluation of changes in non-financial assumptions and experience adjustments to current interest rates (35) [1] (54) [2]  
Insurance contracts other than those to which premium allocation approach has been applied [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets 18    
Beginning balance 176,024    
Opening net balance 176,006    
Opening assets, Reinsurance 17,146    
Opening liabilities, Reinsurance 195    
Variable Fee Approach [Abstract]      
Closing net balance 137,341   176,006
Closing assets 16   18
Closing balance 137,357   176,024
Closing assets, Reinsurance 17,365   17,146
Closing liabilities, Reinsurance 201   195
Insurance contracts other than those to which premium allocation approach has been applied [member] | Insurance contracts issued [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets 18 125 125
Beginning balance 176,024 188,318 188,318
Opening net balance 176,006 188,193 188,193
Changes in estimates that adjust contractual service margin 0   0
Changes in estimates that adjust onerous contracts 859   1,098
New contracts issued – non-onerous 0   0
New contracts issued – onerous 29   42
Changes that relate to future service 888   1,139
Earnings released from contractual service margin (431)   (930)
Release of risk adjustment (132)   (278)
Experience adjustments on current service (58)   439
Revenue recognised for incurred policyholder tax expenses 3   (11)
Changes that relate to current service (618)   (780)
Changes that relate to past service 0   1
Experience adjustments on claims incurred 0   1
Insurance service result 270   361
General Model [Abstract]      
Interest accreted to insurance contracts 1,493   3,021
Changes in interest rates and other financial assumptions 198   1,771
Revaluation of changes in non-financial assumptions and experience adjustments to current interest rates (49)   (128)
Variable Fee Approach [Abstract]      
Change in fair value of the underlying assets 4,309   14,316
Change in fulfilment value - risk mitigation option (616)   (836)
Insurance finance income / (expenses) 5,334   18,143
Premiums received 6,651   14,405
Claims, benefits and expenses paid (11,240)   (24,576)
Acquisition costs paid (638)   (1,126)
Other (11)   (30)
Cash flows (5,238)   (11,326)
Disposal of a business 0   (7)
Transfers to disposal groups (42,977)   0
Other movements (42,977)   (7)
Net exchange differences 3,946   (19,358)
Closing net balance 137,341   176,006
Closing assets 16   18
Closing balance 137,357   176,024
Insurance contracts other than those to which premium allocation approach has been applied [member] | Reinsurance contracts held [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Increase Decrease Through Reversals of Loss Recovery Component Insurance Contracts Liability Asset 1   0
Opening assets, Reinsurance 17,146 16,015 16,015
Opening liabilities, Reinsurance 195 303 303
Net opening balance, Reinsurance 16,950 15,712 15,712
Changes in estimates that adjust contractual service margin 0   0
Changes in estimates that relate to losses and reversals of losses on underlying onerous contracts 450   618
New reinsurance contracts recognized in the year 1   1
Changes that relate to future service 451   620
Earnings released from contractual service margin (18)   (11)
Release of risk adjustment (35)   (72)
Experience adjustments on current service (26)   300
Changes that relate to current service (79)   217
Variable Fee Approach [Abstract]      
Net income/expenses of reinsurance held 372   837
Insurance finance income / (expenses) 162   683
Premiums paid, net of received fixed commission 628   4,950
Amounts received (1,415)   (3,270)
Other 0   (1)
Cash flows (788)   1,680
Transfers to disposal groups 4   0
Net exchange differences 464   (1,961)
Net closing balance, Reinsurance 17,164   16,950
Closing assets, Reinsurance 17,365   17,146
Closing liabilities, Reinsurance 201   195
Insurance contracts other than those to which premium allocation approach has been applied [member] | Investment contracts with DPF [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets, Investment contracts 0 0 0
Opening liabilities, Investment contracts 21,281 22,332 22,332
Net opening balance, Investment contracts 21,281 22,332 22,332
Changes in estimates that adjust contractual service margin 0   0
Changes in estimates that adjust onerous contracts (1)   2
New contracts issued – non-onerous 0   0
Changes that relate to future service (1)   2
Earnings released from contractual service margin (9)   (37)
Release of risk adjustment (4)   (14)
Experience adjustments on current service 0   4
Changes that relate to current service (13)   (47)
Insurance service result (13)   (45)
General Model [Abstract]      
Changes in interest rates and other financial assumptions 1   0
Variable Fee Approach [Abstract]      
Change in fair value of the underlying assets of products with direct participating features (441)   2,916
Insurance finance income / (expenses) (440)   2,916
Premiums received 106   413
Claims, benefits and expenses paid (848)   (3,157)
Acquisition costs paid (2)   (2)
Other (1)   1
Cash flows (746)   (2,744)
Transfers to disposal groups (20,196)   0
Net exchange differences 133   (1,177)
Net closing balance, Investment contracts 20   21,281
Closing assets, Investment contracts 0   0
Closing liabilities, Investment contracts 20   21,281
BEL [Member] | Insurance contracts other than those to which premium allocation approach has been applied [member] | Insurance contracts issued [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets 100 452 452
Beginning balance 164,531 176,063 176,063
Opening net balance 164,430 175,611 175,611
Changes in estimates that adjust contractual service margin (27)   (371)
Changes in estimates that adjust onerous contracts 717   1,069
New contracts issued – non-onerous (468)   (788)
New contracts issued – onerous 19   25
Changes that relate to future service 241   (65)
Earnings released from contractual service margin 0   0
Release of risk adjustment 0   0
Experience adjustments on current service (58)   439
Revenue recognised for incurred policyholder tax expenses 3   (11)
Changes that relate to current service (55)   428
Changes that relate to past service 0   1
Experience adjustments on claims incurred 0   1
Insurance service result 186   364
General Model [Abstract]      
Interest accreted to insurance contracts 1,301   2,654
Changes in interest rates and other financial assumptions 196   1,775
Revaluation of changes in non-financial assumptions and experience adjustments to current interest rates (45)   (138)
Variable Fee Approach [Abstract]      
Change in fair value of the underlying assets 4,309   14,316
Change in fulfilment value - risk mitigation option (616)   (836)
Insurance finance income / (expenses) 5,145   17,770
Premiums received 6,651   14,405
Claims, benefits and expenses paid (11,240)   (24,576)
Acquisition costs paid (638)   (1,126)
Other (11)   (30)
Cash flows (5,238)   (11,326)
Disposal of a business 0   (7)
Transfers to disposal groups (41,515)   0
Other movements (41,515)   (7)
Net exchange differences 3,651   (17,981)
Closing net balance 126,659   164,430
Closing assets 104   100
Closing balance 126,764   164,531
BEL [Member] | Insurance contracts other than those to which premium allocation approach has been applied [member] | Reinsurance contracts held [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Increase Decrease Through Reversals of Loss Recovery Component Insurance Contracts Liability Asset 0   0
Opening assets, Reinsurance 15,816 15,374 15,374
Opening liabilities, Reinsurance 172 693 693
Net opening balance, Reinsurance 15,644 14,681 14,681
Changes in estimates that adjust contractual service margin (53)   (234)
Changes in estimates that relate to losses and reversals of losses on underlying onerous contracts 476   591
New reinsurance contracts recognized in the year (11)   (200)
Changes that relate to future service 411   157
Earnings released from contractual service margin 0   0
Release of risk adjustment 0   0
Experience adjustments on current service (26)   300
Changes that relate to current service (26)   300
Variable Fee Approach [Abstract]      
Net income/expenses of reinsurance held 386   457
Insurance finance income / (expenses) 144   652
Premiums paid, net of received fixed commission 628   4,950
Amounts received (1,415)   (3,270)
Other 0   (1)
Cash flows (788)   1,680
Transfers to disposal groups 6   0
Net exchange differences 427   (1,826)
Net closing balance, Reinsurance 15,819   15,644
Closing assets, Reinsurance 15,998   15,816
Closing liabilities, Reinsurance 179   172
BEL [Member] | Insurance contracts other than those to which premium allocation approach has been applied [member] | Investment contracts with DPF [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets, Investment contracts 0 0 0
Opening liabilities, Investment contracts 20,940 21,987 21,987
Net opening balance, Investment contracts 20,940 21,987 21,987
Changes in estimates that adjust contractual service margin 24   (66)
Changes in estimates that adjust onerous contracts (1)   2
New contracts issued – non-onerous (2)   0
Changes that relate to future service 22   (64)
Earnings released from contractual service margin 0   0
Release of risk adjustment 0   0
Experience adjustments on current service 0   4
Changes that relate to current service 0   4
Insurance service result 22   (60)
Variable Fee Approach [Abstract]      
Change in fair value of the underlying assets of products with direct participating features (441)   2,916
Insurance finance income / (expenses) (440)   2,916
Premiums received 106   413
Claims, benefits and expenses paid (848)   (3,157)
Acquisition costs paid (2)   (2)
Other (1)   1
Cash flows (746)   (2,744)
Transfers to disposal groups (19,891)   0
Net exchange differences 131   (1,159)
Net closing balance, Investment contracts 15   20,940
Closing assets, Investment contracts 0   0
Closing liabilities, Investment contracts 15   20,940
RA [member] | Insurance contracts other than those to which premium allocation approach has been applied [member] | Insurance contracts issued [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets (35) (323) (323)
Beginning balance 3,134 3,295 3,295
Opening net balance 3,169 3,618 3,618
Changes in estimates that adjust contractual service margin (70)   (78)
Changes in estimates that adjust onerous contracts 143   29
New contracts issued – non-onerous 79   118
New contracts issued – onerous 10   17
Changes that relate to future service 162   86
Earnings released from contractual service margin 0   0
Release of risk adjustment (132)   (278)
Experience adjustments on current service 0   0
Revenue recognised for incurred policyholder tax expenses 0   0
Changes that relate to current service (132)   (278)
Changes that relate to past service 0   0
Experience adjustments on claims incurred 0   0
Insurance service result 30   (191)
General Model [Abstract]      
Interest accreted to insurance contracts 62   141
Changes in interest rates and other financial assumptions 1   (4)
Revaluation of changes in non-financial assumptions and experience adjustments to current interest rates (4)   10
Variable Fee Approach [Abstract]      
Change in fair value of the underlying assets 0   0
Change in fulfilment value - risk mitigation option 0   0
Insurance finance income / (expenses) 59   148
Premiums received 0   0
Claims, benefits and expenses paid 0   0
Acquisition costs paid 0   0
Other 0   0
Cash flows 0   0
Disposal of a business 0   0
Transfers to disposal groups (218)   0
Other movements (218)   0
Net exchange differences 85   (405)
Closing net balance 3,126   3,169
Closing assets (38)   (35)
Closing balance 3,087   3,134
RA [member] | Insurance contracts other than those to which premium allocation approach has been applied [member] | Reinsurance contracts held [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Increase Decrease Through Reversals of Loss Recovery Component Insurance Contracts Liability Asset 0   0
Opening assets, Reinsurance 691 433 433
Opening liabilities, Reinsurance (30) (361) (361)
Net opening balance, Reinsurance 721 794 794
Changes in estimates that adjust contractual service margin 13   (20)
Changes in estimates that relate to losses and reversals of losses on underlying onerous contracts (13)   9
New reinsurance contracts recognized in the year 3   60
Changes that relate to future service 2   50
Earnings released from contractual service margin 0   0
Release of risk adjustment (35)   (72)
Experience adjustments on current service 0   0
Changes that relate to current service (35)   (72)
Variable Fee Approach [Abstract]      
Net income/expenses of reinsurance held (32)   (22)
Insurance finance income / (expenses) 18   43
Premiums paid, net of received fixed commission 0   0
Amounts received 0   0
Other 0   0
Cash flows 0   0
Transfers to disposal groups 0   0
Net exchange differences 20   (94)
Net closing balance, Reinsurance 726   721
Closing assets, Reinsurance 685   691
Closing liabilities, Reinsurance (41)   (30)
RA [member] | Insurance contracts other than those to which premium allocation approach has been applied [member] | Investment contracts with DPF [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets, Investment contracts 0 0 0
Opening liabilities, Investment contracts 97 112 112
Net opening balance, Investment contracts 97 112 112
Changes in estimates that adjust contractual service margin (4)   5
Changes in estimates that adjust onerous contracts 0   0
New contracts issued – non-onerous 0   0
Changes that relate to future service (4)   5
Earnings released from contractual service margin 0   0
Release of risk adjustment (4)   (14)
Experience adjustments on current service 0   0
Changes that relate to current service (4)   (14)
Insurance service result (7)   (10)
General Model [Abstract]      
Changes in interest rates and other financial assumptions 0   0
Variable Fee Approach [Abstract]      
Change in fair value of the underlying assets of products with direct participating features 0   0
Insurance finance income / (expenses) 0   0
Premiums received 0   0
Claims, benefits and expenses paid 0   0
Acquisition costs paid 0   0
Other 0   0
Cash flows 0   0
Transfers to disposal groups (90)   0
Net exchange differences 1   (6)
Net closing balance, Investment contracts 0   97
Closing assets, Investment contracts 0   0
Closing liabilities, Investment contracts 0   97
CSM [member] | Insurance contracts issued [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening net balance 8,406 8,964 8,964
Changes in estimates that adjust contractual service margin 96   449
Earnings released from contractual service margin (431)   (930)
Variable Fee Approach [Abstract]      
Insurance finance income / (expenses) 130   226
Net exchange differences 210   (972)
Closing net balance 7,556   8,406
CSM [member] | Reinsurance contracts held [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening net balance 585 237 237
Changes in estimates that adjust contractual service margin 41   254
Earnings released from contractual service margin (18)   (11)
Variable Fee Approach [Abstract]      
Insurance finance income / (expenses) 0   (12)
Net exchange differences 17   (42)
Closing net balance 619   585
CSM [member] | Investment contracts with DPF [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening net balance 245 233 233
Changes in estimates that adjust contractual service margin (20)   61
Earnings released from contractual service margin (9)   (37)
Variable Fee Approach [Abstract]      
Insurance finance income / (expenses) 0    
Transfers to disposal groups (214)    
Net exchange differences 2   (13)
Closing net balance 4   245
CSM [member] | Insurance contracts other than those to which premium allocation approach has been applied [member] | Insurance contracts issued [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets (47) (5) (5)
Beginning balance 8,359 8,959 8,959
Opening net balance 8,406 8,964 8,964
Changes in estimates that adjust contractual service margin 96   449
Changes in estimates that adjust onerous contracts 0   0
New contracts issued – non-onerous 390   669
New contracts issued – onerous 0   0
Changes that relate to future service 486   1,118
Earnings released from contractual service margin (431)   (930)
Release of risk adjustment 0   0
Experience adjustments on current service 0   0
Revenue recognised for incurred policyholder tax expenses 0   0
Changes that relate to current service (431)   (930)
Changes that relate to past service 0   0
Experience adjustments on claims incurred 0   0
Insurance service result 54   189
General Model [Abstract]      
Interest accreted to insurance contracts 130   226
Changes in interest rates and other financial assumptions 0   0
Revaluation of changes in non-financial assumptions and experience adjustments to current interest rates 0   0
Variable Fee Approach [Abstract]      
Change in fair value of the underlying assets 0   0
Change in fulfilment value - risk mitigation option 0   0
Insurance finance income / (expenses) 130   226
Premiums received 0   0
Claims, benefits and expenses paid 0   0
Acquisition costs paid 0   0
Other 0   0
Cash flows 0   0
Disposal of a business 0   0
Transfers to disposal groups (1,244)   0
Other movements (1,244)   0
Net exchange differences 210   (972)
Closing net balance 7,556   8,406
Closing assets (49)   (47)
Closing balance 7,507   8,359
CSM [member] | Insurance contracts other than those to which premium allocation approach has been applied [member] | Reinsurance contracts held [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Increase Decrease Through Reversals of Loss Recovery Component Insurance Contracts Liability Asset 1   0
Opening assets, Reinsurance 639 208 208
Opening liabilities, Reinsurance 54 (29) (29)
Net opening balance, Reinsurance 585 237 237
Changes in estimates that adjust contractual service margin 41   254
Changes in estimates that relate to losses and reversals of losses on underlying onerous contracts (12)   18
New reinsurance contracts recognized in the year 9   141
Changes that relate to future service 37   413
Earnings released from contractual service margin (18)   (11)
Release of risk adjustment 0   0
Experience adjustments on current service 0   0
Changes that relate to current service (18)   (11)
Variable Fee Approach [Abstract]      
Net income/expenses of reinsurance held 19   402
Insurance finance income / (expenses) 0   (12)
Premiums paid, net of received fixed commission 0   0
Amounts received 0   0
Other 0   0
Cash flows 0   0
Transfers to disposal groups (2)   0
Net exchange differences 17   (42)
Net closing balance, Reinsurance 619   585
Closing assets, Reinsurance 682   639
Closing liabilities, Reinsurance 62   54
CSM [member] | Insurance contracts other than those to which premium allocation approach has been applied [member] | Investment contracts with DPF [member]      
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]      
Opening assets, Investment contracts 0 0 0
Opening liabilities, Investment contracts 245 233 233
Net opening balance, Investment contracts 245 € 233 233
Changes in estimates that adjust contractual service margin (20)   61
Changes in estimates that adjust onerous contracts 0   0
New contracts issued – non-onerous 1   0
Changes that relate to future service (19)   61
Earnings released from contractual service margin (9)   (37)
Release of risk adjustment 0   0
Experience adjustments on current service 0   0
Changes that relate to current service (9)   (37)
Insurance service result (28)   25
General Model [Abstract]      
Changes in interest rates and other financial assumptions 0   0
Variable Fee Approach [Abstract]      
Change in fair value of the underlying assets of products with direct participating features 0   0
Insurance finance income / (expenses) 0   0
Premiums received 0   0
Claims, benefits and expenses paid 0   0
Acquisition costs paid 0   0
Other 0   0
Cash flows 0   0
Transfers to disposal groups (214)   0
Net exchange differences 2   (13)
Net closing balance, Investment contracts 4   245
Closing assets, Investment contracts 0   0
Closing liabilities, Investment contracts € 4   € 245
[1] Investment contracts with DPF - Without direct part. includes EUR (2) million in line Total insurance finance income / (expenses) and Insurance net investment result.
[2] 1H 2025 figures are restated as Aegon UK is classified as discontinued operations.