Shares in Group Companies - Summary of Shares in Group Companies (Detail) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of interests in other entities [Line Items]
Dividend received	€ (94)	€ (118)
Aegon N.V [member]
Disclosure of interests in other entities [Line Items]
At January 1	23,117	22,219
Capital contributions and acquisitions	97	1,006
Divestments and capital repayments	(23)	(698)
Dividend received	(702)	(120)
Net income / (loss) for the financial year	832	2,511	€ 533
Revaluations	(1,154)	(1,799)
Ending balance	€ 22,168	€ 23,117	€ 22,219

The amount of investments accounted for using the equity method. The equity method is a method of accounting whereby the investment is initially recognised at cost and adjusted thereafter for the post-acquisition change in the investor's share of net assets of the investee. The investor's profit or loss includes its share of the profit or loss of the investee. The investor's other comprehensive income includes its share of the other comprehensive income of the investee. [Refer: At cost [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2018-01-01
-Paragraph 24
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2018-03-01&anchor=para_24_a&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2018-01-01
-Paragraph B16
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2018-03-01&anchor=para_B16&doctype=Appendix&seq=2
-URIDate 2018-03-16

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 54
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_54_e&doctype=Standard
-URIDate 2018-03-16

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