Deferred Acquisition Costs and Other Actuarial Balances - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Long-duration and short-duration insurance
Deferred Acquisition Costs
Amortization of deferred acquisition costs	$ 98.7	$ 97.3	$ 197.2	$ 194.6

Amount of amortization expense (reversal of expense) for deferred policy acquisition costs.

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+ Details