Business Dispositions - Additional Information (Details) - Continental Europe Operations [Member] - USD ($) $ in Millions	3 Months Ended	6 Months Ended	9 Months Ended
Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration	$ 12	$ 12	$ 12	$ 14
Net realized capital gains
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Disposition of Business	$ 19	$ 18	$ (66)

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4582445-111684

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration