v3.26.1
Defined Benefit Plans - Summary of Defined Benefit Plans (Detail) - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of defined benefit plans [Line Items]      
Defined benefit plans € 384 € 457 € 546
Defined benefit assets 124 119  
Defined benefit liabilities 507 576  
Reimbursement rights 28 9  
Aegon Ltd. [member]      
Disclosure of defined benefit plans [Line Items]      
Defined benefit plans 51 53  
Defined benefit liabilities 51 53  
Reimbursement rights 16 5  
Present value of the expected guaranteed premiums and management fees (33) (44)  
Retirement Benefit Plans [member]      
Disclosure of defined benefit plans [Line Items]      
Defined benefit plans 217 269 368
Retirement Benefit Plans [member] | Aegon Ltd. [member]      
Disclosure of defined benefit plans [Line Items]      
Defined benefit plans 49 50  
Defined benefit liabilities 49 50  
Other Post Employment Benefit Plans [member]      
Disclosure of defined benefit plans [Line Items]      
Defined benefit plans 167 189 € 178
Other Post Employment Benefit Plans [member] | Aegon Ltd. [member]      
Disclosure of defined benefit plans [Line Items]      
Defined benefit plans 2 3  
Defined benefit liabilities 2 3  
Retirement benefit plans in surplus [member]      
Disclosure of defined benefit plans [Line Items]      
Defined benefit assets 95 110  
Reimbursement Rights [Member]      
Disclosure of defined benefit plans [Line Items]      
Defined benefit assets 28 9  
Retirement benefit plans in deficit [member]      
Disclosure of defined benefit plans [Line Items]      
Defined benefit liabilities 340 388  
Reimbursement Rights Retirement Benefit Plans [Member] | Aegon Ltd. [member]      
Disclosure of defined benefit plans [Line Items]      
Reimbursement rights 49 50  
Other post-employment benefit plans in deficit [member]      
Disclosure of defined benefit plans [Line Items]      
Defined benefit liabilities € 167 € 189