v3.26.1
(Re)Insurance contracts and investment contracts with discretionary participation features - Summary of Movement Schedules by Measurement Component (Detail) - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]    
Opening assets € 125  
Beginning balance 188,359  
Opening net balance 188,233  
Opening assets, Reinsurance 16,021  
Opening liabilities, Reinsurance 303  
Net opening balance, Investment contracts 22,332 € 21,594
Variable Fee Approach [Abstract]    
Closing net balance 176,049 188,233
Closing assets 18 125
Closing balance 176,067 188,359
Closing assets, Reinsurance 17,153 16,021
Closing liabilities, Reinsurance 195 303
Net closing balance, Investment contracts 21,281 22,332
Investment contract with discretionary participation features [member]    
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]    
Opening assets, Investment contracts 0 0
Opening liabilities, Investment contracts 22,332 21,594
Net opening balance, Investment contracts 22,332 21,594
Changes in estimates that adjust contractual service margin 0 0
Changes in estimates that adjust onerous contracts 2 0
Changes that relate to future service 2 0
Earnings released from contractual service margin (37) (33)
Release of risk adjustment (14) (14)
Experience adjustments on current service 4 11
Changes that relate to current service (47) (37)
Insurance service result (45) (37)
Variable Fee Approach [Abstract]    
Change in fair value of the underlying assets of products with direct participating features 2,916 2,270
Insurance finance income / (expenses) 2,916 2,270
Premiums received 413 470
Claims, benefits and expenses paid (3,157) (2,995)
Acquisition costs paid (2) 0
Other 1 0
Cash flows (2,744) (2,525)
Net exchange differences (1,177) 1,030
Net closing balance, Investment contracts 21,281 22,332
Closing assets, Investment contracts 0 0
Closing liabilities, Investment contracts 21,281 22,332
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 125  
Beginning balance 188,318  
Opening net balance 188,193  
Opening assets, Reinsurance 16,015  
Opening liabilities, Reinsurance 303  
Variable Fee Approach [Abstract]    
Closing net balance 176,006 188,193
Closing assets 18 125
Closing balance 176,024 188,318
Closing assets, Reinsurance 17,146 16,015
Closing liabilities, Reinsurance 195 303
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 125 185
Beginning balance 188,318 177,407
Opening net balance 188,193 177,222
Changes in estimates that adjust contractual service margin 0 0
Changes in estimates that adjust onerous contracts 1,098 1,064
New contracts issued – non-onerous 0 0
New contracts issued – onerous 42 54
Changes that relate to future service 1,139 1,118
Earnings released from contractual service margin (930) (958)
Release of risk adjustment (278) (305)
Experience adjustments on current service 439 101
Revenue recognised for incurred policyholder tax expenses (11) 2
Changes that relate to current service (780) (1,160)
Changes that relate to past service 1 14
Experience adjustments on claims incurred 1 14
Insurance service result 361 (27)
General Model [Abstract]    
Interest accreted to insurance contracts 3,021 3,096
Changes in interest rates and other financial assumptions 1,771 (1,921)
Revaluation of changes in non-financial assumptions and experience adjustments to current interest rates (128) 121
Variable Fee Approach [Abstract]    
Change in fair value of the underlying assets 14,316 12,719
Change in fulfilment value - risk mitigation option (836) (2,029)
Insurance finance income / (expenses) 18,143 11,986
Premiums received 14,405 15,377
Claims, benefits and expenses paid (24,576) (26,274)
Acquisition costs paid (1,126) (963)
Other (30) (32)
Cash flows (11,326) (11,892)
Contracts disposed during the period 0 (85)
Disposal of a business (7) 0
Transfers to disposal groups 0 (3)
Other 0 (4)
Other movements (7) (92)
Net exchange differences (19,358) 10,996
Closing net balance 176,006 188,193
Closing assets 18 125
Closing balance 176,024 188,318
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]    
Opening assets, Reinsurance 16,015 16,601
Opening liabilities, Reinsurance 303 608
Net opening balance, Reinsurance 15,712 15,993
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 618 454
New reinsurance contracts recognized in the year 1 1
Changes that relate to future service 620 455
Earnings released from contractual service margin (11) (14)
Release of risk adjustment (72) (83)
Experience adjustments on current service 300 (36)
Changes that relate to current service 217 (133)
Changes that relate to past service 0 3
Experience adjustments on claims incurred 0 3
Variable Fee Approach [Abstract]    
Net income/expenses of reinsurance held 837 325
Insurance finance income / (expenses) 683 55
Premiums paid, net of received fixed commission 4,950 1,341
Amounts received (3,270) (3,209)
Other (1) (1)
Cash flows 1,680 (1,869)
Reinsurance contracts disposed in the year 0 (30)
Other 0 196
Other movements 0 226
Net exchange differences (1,961) 1,011
Net closing balance, Reinsurance 16,950 15,712
Closing assets, Reinsurance 17,146 16,015
Closing liabilities, Reinsurance 195 303
BEL [Member] | Investment contract with discretionary participation features [member]    
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]    
Opening assets, Investment contracts 0 0
Opening liabilities, Investment contracts 21,987 21,285
Net opening balance, Investment contracts 21,987 21,285
Changes in estimates that adjust contractual service margin (66) (70)
Changes in estimates that adjust onerous contracts 2 0
Changes that relate to future service (64) (70)
Earnings released from contractual service margin 0 0
Release of risk adjustment 0 0
Experience adjustments on current service 4 11
Changes that relate to current service 4 11
Insurance service result (60) (59)
Variable Fee Approach [Abstract]    
Change in fair value of the underlying assets of products with direct participating features 2,916 2,270
Insurance finance income / (expenses) 2,916 2,270
Premiums received 413 470
Claims, benefits and expenses paid (3,157) (2,995)
Acquisition costs paid (2) 0
Other 1 0
Cash flows (2,744) (2,525)
Net exchange differences (1,159) 1,015
Net closing balance, Investment contracts 20,940 21,987
Closing assets, Investment contracts 0 0
Closing liabilities, Investment contracts 20,940 21,987
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 452 475
Beginning balance 176,063 166,036
Opening net balance 175,611 165,562
Changes in estimates that adjust contractual service margin (371) (317)
Changes in estimates that adjust onerous contracts 1,069 1,063
New contracts issued – non-onerous (788) (648)
New contracts issued – onerous 25 36
Changes that relate to future service (65) 134
Earnings released from contractual service margin 0 0
Release of risk adjustment 0 0
Experience adjustments on current service 439 101
Revenue recognised for incurred policyholder tax expenses (11) 2
Changes that relate to current service 428 103
Changes that relate to past service 1 15
Experience adjustments on claims incurred 1 15
Insurance service result 364 252
General Model [Abstract]    
Interest accreted to insurance contracts 2,654 2,693
Changes in interest rates and other financial assumptions 1,775 (1,910)
Revaluation of changes in non-financial assumptions and experience adjustments to current interest rates (138) 121
Variable Fee Approach [Abstract]    
Change in fair value of the underlying assets 14,316 12,719
Change in fulfilment value - risk mitigation option (836) (2,029)
Insurance finance income / (expenses) 17,770 11,594
Premiums received 14,405 15,377
Claims, benefits and expenses paid (24,576) (26,274)
Acquisition costs paid (1,126) (963)
Other (30) (32)
Cash flows (11,326) (11,892)
Contracts disposed during the period 0 (128)
Disposal of a business (7) 0
Transfers to disposal groups 0 (14)
Other 0 (4)
Other movements (7) (147)
Net exchange differences (17,981) 10,242
Closing net balance 164,430 175,611
Closing assets 100 452
Closing balance 164,531 176,063
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]    
Opening assets, Reinsurance 15,374 16,184
Opening liabilities, Reinsurance 693 1,024
Net opening balance, Reinsurance 14,681 15,160
Changes in estimates that adjust contractual service margin (234) (152)
Changes in estimates that relate to losses and reversals of losses on underlying onerous contracts 591 462
New reinsurance contracts recognized in the year (200) (11)
Changes that relate to future service 157 299
Earnings released from contractual service margin 0 0
Release of risk adjustment 0 0
Experience adjustments on current service 300 (36)
Changes that relate to current service 300 (36)
Changes that relate to past service 0 3
Experience adjustments on claims incurred 0 3
Variable Fee Approach [Abstract]    
Net income/expenses of reinsurance held 457 266
Insurance finance income / (expenses) 652 31
Premiums paid, net of received fixed commission 4,950 1,341
Amounts received (3,270) (3,209)
Other (1) (1)
Cash flows 1,680 (1,869)
Reinsurance contracts disposed in the year 0 (64)
Other 0 143
Other movements 0 207
Net exchange differences (1,826) 949
Net closing balance, Reinsurance 15,644 14,681
Closing assets, Reinsurance 15,816 15,374
Closing liabilities, Reinsurance 172 693
RA [member] | Investment contract with discretionary participation features [member]    
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]    
Opening assets, Investment contracts 0 0
Opening liabilities, Investment contracts 112 128
Net opening balance, Investment contracts 112 128
Changes in estimates that adjust contractual service margin 5 (7)
Changes in estimates that adjust onerous contracts 0 0
Changes that relate to future service 5 (7)
Earnings released from contractual service margin 0 0
Release of risk adjustment (14) (14)
Experience adjustments on current service 0 0
Changes that relate to current service (14) (14)
Insurance service result (10) (21)
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
Net exchange differences (6) 6
Net closing balance, Investment contracts 97 112
Closing assets, Investment contracts 0 0
Closing liabilities, Investment contracts 97 112
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 (323) (286)
Beginning balance 3,295 3,251
Opening net balance 3,618 3,537
Changes in estimates that adjust contractual service margin (78) (131)
Changes in estimates that adjust onerous contracts 29 1
New contracts issued – non-onerous 118 102
New contracts issued – onerous 17 18
Changes that relate to future service 86 (10)
Earnings released from contractual service margin 0 0
Release of risk adjustment (278) (305)
Experience adjustments on current service 0 0
Revenue recognised for incurred policyholder tax expenses 0 0
Changes that relate to current service (278) (305)
Changes that relate to past service 0 (1)
Experience adjustments on claims incurred 0 (1)
Insurance service result (191) (315)
General Model [Abstract]    
Interest accreted to insurance contracts 141 178
Changes in interest rates and other financial assumptions (4) (11)
Revaluation of changes in non-financial assumptions and experience adjustments to current interest rates 10 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) 148 167
Premiums received 0 0
Claims, benefits and expenses paid 0 0
Acquisition costs paid 0 0
Other 0 0
Cash flows 0 0
Contracts disposed during the period 0 0
Disposal of a business 0 0
Transfers to disposal groups 0 6
Other 0 0
Other movements 0 6
Net exchange differences (405) 224
Closing net balance 3,169 3,618
Closing assets (35) (323)
Closing balance 3,134 3,295
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]    
Opening assets, Reinsurance 433 423
Opening liabilities, Reinsurance (361) (332)
Net opening balance, Reinsurance 794 755
Changes in estimates that adjust contractual service margin (20) (11)
Changes in estimates that relate to losses and reversals of losses on underlying onerous contracts 9 38
New reinsurance contracts recognized in the year 60 4
Changes that relate to future service 50 31
Earnings released from contractual service margin 0 0
Release of risk adjustment (72) (83)
Experience adjustments on current service 0 0
Changes that relate to current service (72) (83)
Changes that relate to past service 0 0
Experience adjustments on claims incurred 0 0
Variable Fee Approach [Abstract]    
Net income/expenses of reinsurance held (22) (52)
Insurance finance income / (expenses) 43 36
Premiums paid, net of received fixed commission 0 0
Amounts received 0 0
Other 0 0
Cash flows 0 0
Reinsurance contracts disposed in the year 0 0
Other 0 5
Other movements 0 5
Net exchange differences (94) 50
Net closing balance, Reinsurance 721 794
Closing assets, Reinsurance 691 433
Closing liabilities, Reinsurance (30) (361)
CSM [member] | Insurance contracts issued [member]    
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]    
Opening net balance 8,964 8,124
Changes in estimates that adjust contractual service margin 449 448
Earnings released from contractual service margin (930) (958)
Variable Fee Approach [Abstract]    
Insurance finance income / (expenses) 226 225
Other   6
Cash flows   43
Net exchange differences (972) 529
Closing net balance 8,406 8,964
CSM [member] | Reinsurance contracts held [member]    
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]    
Opening net balance 237 78
Changes in estimates that adjust contractual service margin 254 163
Earnings released from contractual service margin (11) (14)
Variable Fee Approach [Abstract]    
Insurance finance income / (expenses) (12) (12)
Other   14
Cash flows   34
Net exchange differences (42) 12
Closing net balance 585 237
CSM [member] | Investment contract with discretionary participation features [member]    
Disclosure of movement by measurement component insurance reinsurance contracts and investment contracts [line items]    
Opening net balance 233 180
Opening assets, Investment contracts 0 0
Opening liabilities, Investment contracts 233 180
Net opening balance, Investment contracts 233 180
Changes in estimates that adjust contractual service margin 61 76
Changes in estimates that adjust contractual service margin 61 76
Changes in estimates that adjust onerous contracts 0 0
Changes that relate to future service 61 76
Earnings released from contractual service margin (37) (33)
Earnings released from contractual service margin (37) (33)
Release of risk adjustment 0 0
Experience adjustments on current service 0 0
Changes that relate to current service (37) (33)
Insurance service result 25 43
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  
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
Cash flows 0 0
Net exchange differences (13) 10
Net exchange differences (13) 10
Closing net balance 245 233
Net closing balance, Investment contracts 245 233
Closing assets, Investment contracts 0 0
Closing liabilities, Investment contracts 245 233
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 (5) (4)
Beginning balance 8,959 8,120
Opening net balance 8,964 8,124
Changes in estimates that adjust contractual service margin 449 448
Changes in estimates that adjust onerous contracts 0 0
New contracts issued – non-onerous 669 546
New contracts issued – onerous 0 0
Changes that relate to future service 1,118 994
Earnings released from contractual service margin (930) (958)
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 (930) (958)
Changes that relate to past service 0 0
Experience adjustments on claims incurred 0 0
Insurance service result 189 36
General Model [Abstract]    
Interest accreted to insurance contracts 226 225
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) 226 225
Premiums received 0 0
Claims, benefits and expenses paid 0 0
Acquisition costs paid 0 0
Other 0 0
Cash flows 0 0
Contracts disposed during the period 0 43
Disposal of a business 0 0
Transfers to disposal groups 0 6
Other 0 0
Other movements 0 48
Net exchange differences (972) 529
Closing net balance 8,406 8,964
Closing assets (47) (5)
Closing balance 8,359 8,959
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]    
Opening assets, Reinsurance 208 (7)
Opening liabilities, Reinsurance (29) (85)
Net opening balance, Reinsurance 237 78
Changes in estimates that adjust contractual service margin 254 163
Changes in estimates that relate to losses and reversals of losses on underlying onerous contracts 18 (46)
New reinsurance contracts recognized in the year 141 8
Changes that relate to future service 413 125
Earnings released from contractual service margin (11) (14)
Release of risk adjustment 0 0
Experience adjustments on current service 0 0
Changes that relate to current service (11) (14)
Changes that relate to past service 0 0
Experience adjustments on claims incurred 0 0
Variable Fee Approach [Abstract]    
Net income/expenses of reinsurance held 402 111
Insurance finance income / (expenses) (12) (12)
Premiums paid, net of received fixed commission 0 0
Amounts received 0 0
Other 0 0
Cash flows 0 0
Reinsurance contracts disposed in the year 0 34
Other 0 48
Other movements 0 14
Net exchange differences (42) 12
Net closing balance, Reinsurance 585 237
Closing assets, Reinsurance 639 208
Closing liabilities, Reinsurance € 54 € (29)