Investment - Summary of investments in real estate held by entities (Detail) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Detailed Information About Investments In Real Estate Held By Entities [Line Items]
Investment	€ 2,643	€ 2,385	€ 2,901
Value of Aegon's properties which were appraised in the current year	98.00%	99.00%
Appraisals performed by independent external appraisers	98.00%	99.00%
Americas [member]
Disclosure Of Detailed Information About Investments In Real Estate Held By Entities [Line Items]
Investment	€ 39	€ 37
The Netherlands [member]
Disclosure Of Detailed Information About Investments In Real Estate Held By Entities [Line Items]
Investment	€ 2,588	€ 2,331

The amount of property (land or a building - or part of a building - or both) held (by the owner or by the lessee as a right-of-use asset) to earn rentals or for capital appreciation or both, rather than for: (a) use in the production or supply of goods or services or for administrative purposes; or (b) sale in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 40
-IssueDate 2021-01-01
-Paragraph 76
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2021-en-r&anchor=para_76&doctype=Standard
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 40
-IssueDate 2021-01-01
-Paragraph 79
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2021-en-r&anchor=para_79_d&doctype=Standard
-URIDate 2021-03-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2021-01-01
-Paragraph 54
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_b&doctype=Standard
-URIDate 2021-03-24

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