Goodwill and Other Intangibles - Changes in the carrying value of goodwill (Details) - USD ($) $ in Millions		12 Months Ended
Dec. 06, 2021	Dec. 31, 2021
Goodwill [Line Items]
Goodwill, beginning balance		$ 176
Goodwill, ending balance		246
Verikai, Inc.
Goodwill [Line Items]
Goodwill acquired during period	$ 70	$ 70

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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-Subparagraph (SX 210.9-03(10)(1))
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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-SubTopic 20
-Section 45
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant