v3.26.1
Segment Information - Summary of Segment Results (Detail) - EUR (€)
€ in Millions
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Summary of operating result per segment [Line Items]    
Operating result € 970 € 753
Fair value items (29) 156
Realized gains / (losses) on investments 56 (74)
Impairment (losses) / reversals 20 (2)
Non-operating items 48 80
Other income / (charges) (364) (177)
Result before tax from continuing operations 653 656
Income tax (expense) / benefit (45) (50)
Net result from continuing and discontinued operations 608 606
Revenues    
Insurance revenue 4,247 4,558
Interest revenue on financial instruments calculated using the effective interest method 1,542 1,658
Interest income from instruments measured at FVPL 145 154
Other investment income 8 10
Fee and commission income 1,008 1,030
Other revenues 0 0
Total revenues 6,950 7,410
Insurance contracts - Direct participating contracts [member]    
Revenues    
Insurance revenue 464 522
Insurance contracts - Without direct participation contracts [member]    
Revenues    
Insurance revenue 3,783 4,036
Investment contracts with DPF - Direct participating contracts [member]    
Revenues    
Insurance revenue 0  
Investment contracts with DPF - Without direct participation contracts [member]    
Revenues    
Insurance revenue 0  
International [member] | Geographical Consolidation [member]    
Summary of operating result per segment [Line Items]    
Operating result 123 99
Fair value items 10 (38)
Realized gains / (losses) on investments 1 19
Impairment (losses) / reversals 1 (2)
Non-operating items 13 (21)
Other income / (charges) 11 (1)
Result before tax from continuing operations 147 77
Income tax (expense) / benefit (44) (31)
Net result from continuing and discontinued operations 103 46
Inter-segment operating result 124 56
Revenues    
Insurance revenue 703 943
Interest revenue on financial instruments calculated using the effective interest method 52 31
Interest income from instruments measured at FVPL 2 1
Other investment income 71 65
Fee and commission income 15 13
Other revenues 13 18
Total revenues 857 1,070
Inter-segment revenues 0 0
International [member] | Geographical Consolidation [member] | Insurance contracts - Direct participating contracts [member]    
Revenues    
Insurance revenue 2 1
International [member] | Geographical Consolidation [member] | Insurance contracts - Without direct participation contracts [member]    
Revenues    
Insurance revenue 696 942
International [member] | Geographical Consolidation [member] | Investment contracts with DPF - Direct participating contracts [member]    
Revenues    
Insurance revenue 4  
International [member] | Geographical Consolidation [member] | Investment contracts with DPF - Without direct participation contracts [member]    
Revenues    
Insurance revenue 1  
Asset management [member] | Geographical Consolidation [member]    
Summary of operating result per segment [Line Items]    
Operating result 150 104
Fair value items (5) (2)
Realized gains / (losses) on investments 0 0
Impairment (losses) / reversals 0 (2)
Non-operating items (5) (4)
Other income / (charges) (6) (13)
Result before tax from continuing operations 140 86
Income tax (expense) / benefit (35) (24)
Net result from continuing and discontinued operations 104 63
Inter-segment operating result 2 62
Revenues    
Insurance revenue 0 0
Interest revenue on financial instruments calculated using the effective interest method 1 1
Interest income from instruments measured at FVPL 4 10
Other investment income 9 15
Fee and commission income 498 322
Other revenues 5 1
Total revenues 517 348
Inter-segment revenues 68 76
Asset management [member] | Geographical Consolidation [member] | Insurance contracts - Direct participating contracts [member]    
Revenues    
Insurance revenue 0 0
Asset management [member] | Geographical Consolidation [member] | Insurance contracts - Without direct participation contracts [member]    
Revenues    
Insurance revenue 0 0
Asset management [member] | Geographical Consolidation [member] | Investment contracts with DPF - Direct participating contracts [member]    
Revenues    
Insurance revenue 0  
Asset management [member] | Geographical Consolidation [member] | Investment contracts with DPF - Without direct participation contracts [member]    
Revenues    
Insurance revenue 0  
Holding and other activities [member] | Geographical Consolidation [member]    
Summary of operating result per segment [Line Items]    
Operating result (117) (117)
Fair value items (16) 31
Realized gains / (losses) on investments 0 0
Impairment (losses) / reversals 0 0
Non-operating items (16) 31
Other income / (charges) 212 48
Result before tax from continuing operations 79 (38)
Income tax (expense) / benefit 25 16
Net result from continuing and discontinued operations 104 (22)
Inter-segment operating result 29 132
Revenues    
Insurance revenue 0 0
Interest revenue on financial instruments calculated using the effective interest method 15 25
Interest income from instruments measured at FVPL 0 0
Other investment income 103 496
Fee and commission income 0 0
Other revenues 0 0
Total revenues 118 521
Inter-segment revenues 103 498
Holding and other activities [member] | Geographical Consolidation [member] | Insurance contracts - Direct participating contracts [member]    
Revenues    
Insurance revenue 0 0
Holding and other activities [member] | Geographical Consolidation [member] | Insurance contracts - Without direct participation contracts [member]    
Revenues    
Insurance revenue 0 0
Holding and other activities [member] | Geographical Consolidation [member] | Investment contracts with DPF - Direct participating contracts [member]    
Revenues    
Insurance revenue 0  
Holding and other activities [member] | Geographical Consolidation [member] | Investment contracts with DPF - Without direct participation contracts [member]    
Revenues    
Insurance revenue 0  
Segment total [member]    
Summary of operating result per segment [Line Items]    
Operating result 804 741
Fair value items (7) 158
Realized gains / (losses) on investments 57 (54)
Impairment (losses) / reversals 21 (5)
Non-operating items 71 98
Other income / (charges) (160) (128)
Result before tax from continuing operations 715 711
Income tax (expense) / benefit (107) (106)
Net result from continuing and discontinued operations 608 606
Revenues    
Insurance revenue 4,835 5,379
Interest revenue on financial instruments calculated using the effective interest method 1,570 1,660
Interest income from instruments measured at FVPL 147 154
Other investment income 87 89
Fee and commission income 1,115 1,119
Other revenues 19 19
Total revenues 7,772 8,420
Segment total [member] | Insurance contracts - Direct participating contracts [member]    
Revenues    
Insurance revenue 465 522
Segment total [member] | Insurance contracts - Without direct participation contracts [member]    
Revenues    
Insurance revenue 4,365 4,857
Segment total [member] | Investment contracts with DPF - Direct participating contracts [member]    
Revenues    
Insurance revenue 4  
Segment total [member] | Investment contracts with DPF - Without direct participation contracts [member]    
Revenues    
Insurance revenue 1  
JVs and associates eliminations [member]    
Summary of operating result per segment [Line Items]    
Operating result 166 12
Fair value items (22) (2)
Realized gains / (losses) on investments (1) (20)
Impairment (losses) / reversals (1) 3
Non-operating items (23) (18)
Other income / (charges) (204) (50)
Result before tax from continuing operations (62) (56)
Income tax (expense) / benefit 62 56
Net result from continuing and discontinued operations 0 0
Revenues    
Insurance revenue (587) (821)
Interest revenue on financial instruments calculated using the effective interest method (28) (2)
Interest income from instruments measured at FVPL (2) 0
Other investment income (78) (79)
Fee and commission income (107) (89)
Other revenues (19) (19)
Total revenues (821) (1,009)
JVs and associates eliminations [member] | Insurance contracts - Direct participating contracts [member]    
Revenues    
Insurance revenue 0 0
JVs and associates eliminations [member] | Insurance contracts - Without direct participation contracts [member]    
Revenues    
Insurance revenue (582) (821)
JVs and associates eliminations [member] | Investment contracts with DPF - Direct participating contracts [member]    
Revenues    
Insurance revenue (4)  
JVs and associates eliminations [member] | Investment contracts with DPF - Without direct participation contracts [member]    
Revenues    
Insurance revenue (1)  
Americas [member] | Geographical Consolidation [member]    
Summary of operating result per segment [Line Items]    
Operating result 648 627
Fair value items 25 40
Realized gains / (losses) on investments 56 (73)
Impairment (losses) / reversals 19 (1)
Non-operating items 101 (34)
Other income / (charges) (343) (326)
Result before tax from continuing operations 406 267
Income tax (expense) / benefit (67) (7)
Net result from continuing and discontinued operations 339 260
Inter-segment operating result (61) (423)
Revenues    
Insurance revenue 4,150 4,456
Interest revenue on financial instruments calculated using the effective interest method 1,504 1,608
Interest income from instruments measured at FVPL 141 143
Other investment income 6 9
Fee and commission income 723 859
Other revenues 0 0
Total revenues 6,524 7,076
Inter-segment revenues 73 21
Americas [member] | Geographical Consolidation [member] | Insurance contracts - Direct participating contracts [member]    
Revenues    
Insurance revenue 463 521
Americas [member] | Geographical Consolidation [member] | Insurance contracts - Without direct participation contracts [member]    
Revenues    
Insurance revenue 3,687 3,935
Americas [member] | Geographical Consolidation [member] | Investment contracts with DPF - Direct participating contracts [member]    
Revenues    
Insurance revenue 0  
Americas [member] | Geographical Consolidation [member] | Investment contracts with DPF - Without direct participation contracts [member]    
Revenues    
Insurance revenue 0  
United Kingdom [member] | Geographical Consolidation [member]    
Summary of operating result per segment [Line Items]    
Operating result 0 0 [1]
Fair value items 0 0 [1]
Realized gains / (losses) on investments 0 0 [1]
Impairment (losses) / reversals 0 0 [1]
Non-operating items 0 0 [1]
Other income / (charges) 10 45 [1]
Result before tax from continuing operations 10 45 [1]
Income tax (expense) / benefit 0 0 [1]
Net result from continuing and discontinued operations 10 45 [1]
Inter-segment operating result (41) (40) [1]
Revenues    
Insurance revenue 0 0 [1]
Interest revenue on financial instruments calculated using the effective interest method 0 0 [1]
Interest income from instruments measured at FVPL 0 0 [1]
Other investment income 0 0 [1]
Fee and commission income 0 0 [1]
Other revenues 0 0 [1]
Total revenues 0 0 [1]
Inter-segment revenues 0 0 [1]
United Kingdom [member] | Geographical Consolidation [member] | Insurance contracts - Direct participating contracts [member]    
Revenues    
Insurance revenue 0 0 [1]
United Kingdom [member] | Geographical Consolidation [member] | Insurance contracts - Without direct participation contracts [member]    
Revenues    
Insurance revenue 0 0 [1]
United Kingdom [member] | Geographical Consolidation [member] | Investment contracts with DPF - Direct participating contracts [member]    
Revenues    
Insurance revenue 0  
United Kingdom [member] | Geographical Consolidation [member] | Investment contracts with DPF - Without direct participation contracts [member]    
Revenues    
Insurance revenue 0  
Eliminations [member]    
Summary of operating result per segment [Line Items]    
Operating result (1) 28
Fair value items (22) 126
Realized gains / (losses) on investments 0 0
Impairment (losses) / reversals 0 0
Non-operating items (22) 126
Other income / (charges) (44) 119
Result before tax from continuing operations (67) 273
Income tax (expense) / benefit 14 (59)
Net result from continuing and discontinued operations (53) 214
Inter-segment operating result (53) 214
Revenues    
Insurance revenue (19) (20)
Interest revenue on financial instruments calculated using the effective interest method (2) (4)
Interest income from instruments measured at FVPL 0 0
Other investment income (103) (496)
Fee and commission income (121) (75)
Other revenues 0 0
Total revenues (244) (595)
Eliminations [member] | Insurance contracts - Direct participating contracts [member]    
Revenues    
Insurance revenue 0 0
Eliminations [member] | Insurance contracts - Without direct participation contracts [member]    
Revenues    
Insurance revenue (19) € (20)
Eliminations [member] | Investment contracts with DPF - Direct participating contracts [member]    
Revenues    
Insurance revenue 0  
Eliminations [member] | Investment contracts with DPF - Without direct participation contracts [member]    
Revenues    
Insurance revenue € 0  
[1] 1H 2025 figures are restated as Aegon UK is classified as discontinued operations.