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Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	$ 837.0	$ 562.5
Ark 2021 Subordinated Notes
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	179.2	173.9
Carrying Value	159.7	154.5
HG Global Senior Notes
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	153.8	157.2
Carrying Value	147.8	147.4
Kudu Credit Facility
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	365.3	253.3
Carrying Value	350.4	238.6
Distinguished Credit Facility
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	131.2	0.0
Carrying Value	129.9	0.0
Distinguished other debt
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	12.2	0.0
Carrying Value	10.9	0.0
Other Operations debt
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	38.0	23.1
Carrying Value	$ 38.3	$ 22.0

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