Fair Value of Financial Instruments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Percentage of level 3 invested assets in total investment portfolio	9.10%		9.10%
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Net investment gains (losses) included in net income related to financial assets	$ (0.9)	$ 0.2	$ 4.9	$ 0.3
Net investment gains (losses) included in net income related to financial liabilities	$ (3.7)	$ 0.3	$ (5.6)	$ (1.0)

Percentage of invested assets in the total investment portfolio in Level 3 carried at fair value on a recurring basis.

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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