Premium Income and Premiums Paid to Reinsurers - Additional Information (Detail) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Life insurance general account [member]
Disclosure of insurance premium revenue [line items]
Total decrease in premium income	€ 655	€ 2,039
Americas [Member] \| Universal Life Insurance Contract [Member]
Disclosure of insurance premium revenue [line items]
Increase in premium paid to reinsurers	€ 815	€ 270

The increase (decrease) in insurance contracts liability (asset) resulting from premiums paid for reinsurance contracts held. [Refer: Insurance contracts liability (asset); Reinsurance contracts held [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2023-01-01
-Name IFRS
-Number 17
-IssueDate 2021-01-01
-Paragraph 105
-Subparagraph a
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_105_a_i&doctype=Standard
-URIDate 2021-03-24

Name:	ifrs-full_IncreaseDecreaseThroughPremiumsPaidForReinsuranceContractsHeldInsuranceContractsLiabilityAsset
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration