Investments (Invested Assets on Deposit, Held in Trust and Pledged as Collateral - Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Federal Home Loan Bank Stock	$ 700	$ 699

Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 325
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477974/942-325-45-1

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