Debt - Debt Outstanding (Details) € in Millions, $ in Millions	Dec. 31, 2025 USD ($)	Dec. 31, 2025 EUR (€)	Sep. 02, 2025 USD ($)	Jul. 21, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Debt Instrument
Amount borrowed	$ 852.1
Carrying Value	837.0				$ 562.5
Ark 2021 Subordinated Notes
Debt Instrument
Carrying Value	159.7				154.5
HG Global Senior Notes
Debt Instrument
Carrying Value	147.8				147.4
Kudu Credit Facility
Debt Instrument
Carrying Value	350.4				238.6
Distinguished Credit Facility
Debt Instrument
Carrying Value	129.9				0.0
Distinguished other debt
Debt Instrument
Carrying Value	10.9				0.0
Other Operations debt
Debt Instrument
Carrying Value	$ 38.3				$ 22.0
Subordinated Debt | Ark
Debt Instrument
Effective yield (as a percent)	10.20%	10.20%			11.80%
Subordinated Debt | Ark 2021 Subordinated Notes
Debt Instrument
Unamortized issuance cost	$ (3.1)				$ (3.6)
Carrying Value	159.7				154.5
Subordinated Debt | Ark 2021 Subordinated Notes, Tranche 1
Debt Instrument
Amount borrowed	45.8	€ 39.1			41.1
Subordinated Debt | Ark 2021 Subordinated Notes, Tranche 2
Debt Instrument
Amount borrowed	47.0				47.0
Subordinated Debt | Ark 2021 Subordinated Notes, Tranche 3
Debt Instrument
Amount borrowed	70.0				70.0
Senior Notes | HG Global Senior Notes
Debt Instrument
Amount borrowed	150.0				150.0
Unamortized discount and issuance cost	(2.2)				(2.6)
Carrying Value	$ 147.8				$ 147.4
Effective yield (as a percent)	10.80%	10.80%			11.80%
Secured Debt | Kudu Credit Facility
Debt Instrument
Amount borrowed	$ 358.3				$ 245.3	$ 210.3	$ 215.2
Unamortized issuance cost	(7.9)				(6.7)
Carrying Value	$ 350.4			$ 253.3	$ 238.6
Effective yield (as a percent)	8.90%	8.90%			10.30%
Secured Debt | Total Distinguished debt
Debt Instrument
Carrying Value	$ 140.8				$ 0.0
Secured Debt | Distinguished Credit Facility
Debt Instrument
Amount borrowed	131.4		$ 90.2		0.0
Unamortized discount and issuance cost	(1.5)				0.0
Carrying Value	$ 129.9				0.0
Effective yield (as a percent)	10.30%	10.30%
Secured Debt | Distinguished other debt
Debt Instrument
Carrying Value	$ 10.9				0.0
Effective yield (as a percent)	10.90%	10.90%
Secured Debt | Other Operations debt
Debt Instrument
Amount borrowed	$ 38.7				22.4
Unamortized issuance cost	(0.4)				(0.4)
Carrying Value	$ 38.3				$ 22.0
Effective yield (as a percent)	8.30%	8.30%			10.20%