XML 423 R376.htm IDEA: XBRL DOCUMENT v3.20.1
Shareholder's Equity - Summary of Treasury Stock (Detail) - EUR (€)
shares in Thousands, € in Millions
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Disclosure of treasury shares [line items]      
Total amount € 281 € 337 € 325
Common shares B [member]      
Disclosure of treasury shares [line items]      
Total amount € 3 € 2 € 2
Aegon N.V [member]      
Disclosure of treasury shares [line items]      
Number of shares 91,893 76,419  
Total amount € 281 € 337  
Aegon N.V [member] | Common shares [member] | Aegon N V [member]      
Disclosure of treasury shares [line items]      
Number of shares 65,540 61,418  
Total amount € 269 € 326  
Aegon N.V [member] | Common shares [member] | Subsidiaries [member]      
Disclosure of treasury shares [line items]      
Number of shares 1,043 1,144  
Total amount € 9 € 9  
Aegon N.V [member] | Common shares B [member]      
Disclosure of treasury shares [line items]      
Number of shares 25,310 13,856 15,346
Total amount € 3 € 2 € 2