Amount of asset at fair value held for benefit of separate account policyholder.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480078/944-80-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(11))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 80
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480141/944-80-45-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480109/944-80-50-1

Name:	us-gaap_SeparateAccountAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Separate accounts (Fair value of assets) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Fair Value, Separate Account Investment [Line Items]
Separate account assets	$ 5,864	$ 5,573	$ 5,300
Separate Account, Cash and Cash Equivalents
Fair Value, Separate Account Investment [Line Items]
Separate account assets	76		116
Fixed maturities
Fair Value, Separate Account Investment [Line Items]
Separate account assets	89		102
Mutual funds
Fair Value, Separate Account Investment [Line Items]
Separate account assets	$ 5,699		$ 5,082