Third-Party Reinsurance - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Reinsurance [Line Items]
Total Reinsurance recoverables on unpaid losses	$ 428.9
Reinsurance recoverables on paid losses	19.5
Ark
Reinsurance [Line Items]
Total Reinsurance recoverables on unpaid losses	428.9
Reinsurance recoverables	$ 448.4	$ 0.0
Ark \| Third Point Re
Reinsurance [Line Items]
Annual crediting rate	3.00%
Decrease in investment	$ 31.7
Value of investment	20.4
Amount attributable to TPC Providers
Reinsurance [Line Items]
Total Reinsurance recoverables on unpaid losses	$ 276.8

Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

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Rate of interest credited to policyholder deposits.

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Amount before valuation allowance recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

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Amount before valuation allowance of reinsurance recoverables on paid losses.

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Reinsurance [Line Items]

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