Future Contract Benefit - Summary of Gross Premiums and Interest Accretion (UL and Other) (Details) - UL and Other - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	$ 678	$ 542	$ 1,444	$ 1,457
Interest accretion	$ 212	$ 190	$ 421	$ 376

Amount of gross premium income recognized for liability for future policy benefit.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 29E
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480046/944-40-55-29E

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480081/944-40-50-6

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480081/944-40-50-6

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