Investments - Securities Lending Transactions (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Fair value of securities lent	$ 12.3
Collateral that is not permitted to be sold or repledged	0.0
Corporate debt securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Fair value of securities lent	12.2	$ 7.3
Equity securities \| Financial services sector
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Fair value of securities lent	0.1
Cash equivalents
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Fair value of cash collateral	$ 12.7

Fair value of collateral permitted, by contact or custom, to be sold or re-pledged.

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- Definition

Amount, before effects of master netting arrangements, of financial assets loaned to entities in exchange for collateral. Includes liabilities not subject to a master netting arrangement and financial assets transferred other than securities that qualify as secured borrowings.

+ References

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- Definition

The carrying value as of the balance sheet date of the assets received as collateral against securities loaned to other broker-dealers. Borrowers of securities generally are required to provide collateral to the lenders of securities, commonly cash but sometimes other securities or standby letters of credit, with a value slightly higher than that of the securities borrowed. In instances where the entity is permitted to sell or re-pledge these securities, the entity reports the fair value of the collateral received and the related obligation to return the collateral as a liability.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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