XML 371 R377.htm IDEA: XBRL DOCUMENT v3.20.1
Long-Term Borrowings - Summary of Long-Term Borrowings (Detail) - EUR (€)
€ in Millions
Dec. 31, 2019
Dec. 31, 2018
Jan. 01, 2018
 [1]
Disclosure of long-term borrowings [Line Items]      
Borrowings € 9,307 € 12,061 [1] € 13,635
Aegon N.V [member]      
Disclosure of long-term borrowings [Line Items]      
Borrowings 1,257 1,292  
Aegon N.V [member] | Not later than 1 year [member]      
Disclosure of long-term borrowings [Line Items]      
Borrowings   78  
Aegon N.V [member] | 1-5 years [member]      
Disclosure of long-term borrowings [Line Items]      
Borrowings 497 496  
Aegon N.V [member] | Over 10 years [member]      
Disclosure of long-term borrowings [Line Items]      
Borrowings € 760 € 717  
[1] Amounts have been restated to reflect voluntary changes in accounting policies related to liability adequacy testing that was adopted by Aegon effective January 1, 2019. Refer to note 2.1.2 Voluntary changes in accounting policies for details about this change.