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Variable Interest Entities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Jul. 01, 2024	Apr. 30, 2024	Dec. 31, 2023
Variable Interest Entity [Line Items]
Assets held-in-trust	$ 976.4			$ 948.5
BAM Surplus Notes | Surplus Notes
Variable Interest Entity [Line Items]
Stated margin	8.20%	10.00%
Bamboo CRV
Variable Interest Entity [Line Items]
Expected capital contributions	$ 30.0		$ 30.0
Subsidiary - HG Global
Variable Interest Entity [Line Items]
Purchase of surplus notes	$ 503.0
Subsidiary - HG Global | Maximum
Variable Interest Entity [Line Items]
Percentage of par value of policy reinsured	15.00%
Outrigger Re
Variable Interest Entity [Line Items]
Short-term investments, at fair value	$ 199.9			$ 265.3
PassportCard/DavidShield | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Ownership interest	53.80%
Partnership interest, carrying value	$ 159.2
Elementum | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Ownership interest	26.60%
Partnership interest, carrying value	$ 35.0
Limited Partnerships | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Partnership interest, carrying value	$ 262.0

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Amount of the reinsurer's funds held on its behalf by the ceding insurer, including funds held in trust, under reinsurance treaties or contracts with the assuming insurer as security for the payment of the obligations thereunder.

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Equity Capital, Expected Contribution Payments

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