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Debt - Summary of Debt Outstanding (Details) € in Millions, $ in Millions	Jun. 30, 2023 USD ($)	Jun. 30, 2023 EUR (€)	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument
Total debt	$ 566.1			$ 575.2
Ark Subordinated Debt
Debt Instrument
Unamortized issuance cost	(4.5)			(4.6)
Ark 2007 Subordinated Notes, carrying value | Ark Subordinated Debt
Debt Instrument
Amount borrowed	30.0			30.0
Ark 2021 Subordinated Notes Tranche 1
Debt Instrument
Amount borrowed | €		€ 39.1
Ark 2021 Subordinated Notes Tranche 1 | Ark Subordinated Debt
Debt Instrument
Amount borrowed	42.6			41.3
Ark 2021 Subordinated Notes Tranche 2 | Ark Subordinated Debt
Debt Instrument
Amount borrowed	47.0			47.0
Ark 2021 Subordinated Notes Tranche 3 | Ark Subordinated Debt
Debt Instrument
Amount borrowed	70.0			70.0
Ark 2021 Notes | Ark Subordinated Debt
Debt Instrument
Total debt	$ 155.1			$ 153.7
Ark
Debt Instrument
Effective percentage	10.50%	10.50%		7.60%
Ark | Ark Subordinated Debt
Debt Instrument
Total debt	$ 185.1			$ 183.7
Kudu Credit Facility | Asset Management (Kudu)
Debt Instrument
Total debt	203.7			208.3
Other Debt | Other
Debt Instrument
Total debt	$ 30.6			$ 36.7
HG Senior Notes
Debt Instrument
Effective percentage	11.50%	11.50%		8.90%
Secured Debt | HG Senior Notes
Debt Instrument
Amount borrowed	$ 150.0			$ 150.0
Unamortized issuance cost	(3.3)			(3.5)
Total debt	146.7			146.5
Term Loan | Kudu Credit Facility
Debt Instrument
Amount borrowed	210.3			215.2
Unamortized issuance cost	$ (6.6)			$ (6.9)
Effective percentage	9.60%	9.60%		6.10%
Term Loan | Kudu Credit Facility | Asset Management (Kudu)
Debt Instrument
Total debt	$ 210.3		$ 198.3	$ 215.2	$ 260.4	$ 225.4	$ 225.4
Term Loan | Other Operations
Debt Instrument
Amount borrowed	31.2			37.4
Unamortized issuance cost	$ (0.6)			$ (0.7)
Effective percentage	9.10%	9.10%		6.60%

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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