Reinsurance (Summary of Reinsurance Activity) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Insurance [Abstract]
Net assumed written premiums	$ 22.6	$ 18.8	$ 71.5	$ 55.6
Net premiums earned	20.8	16.4	58.0	45.6
Provision for claims	16.5	12.9	54.1	34.0
Amortization of capitalized acquisition costs	$ 0.3	$ 0.3	$ 1.3	$ 1.1

The amount of expense recognized in the current period that reflects the allocation of capitalized costs associated with acquisition of business. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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- Definition

Amount of written premiums assumed from other entities.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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No definition available.

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- Definition

Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 220
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- Definition

Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

+ References

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