Related Parties - Related Party Transactions with Blackstone (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Investment expenses	$ 480	$ 348	$ 372
Related Parties
Related Party Transaction [Line Items]
Investment expenses	$ 147	$ 18

Amount of expenses related to the generation of investment income.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.9)
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.2)
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Name:	us-gaap_InvestmentIncomeInvestmentExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration