Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	$ 575.2	$ 420.9
Fair value | HG Global Senior Notes
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, fair value	155.7	0.0
Fair value | Ark 2007 Notes
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, fair value	28.4	27.6
Fair value | Ark 2021 Notes
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, fair value	163.1	162.8
Fair value | Kudu Credit Facility
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, fair value	223.9	246.8
Fair value | Other Operations
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, fair value	38.2	17.7
Carrying Value | HG Global Senior Notes
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	146.5	0.0
Carrying Value | Ark 2007 Notes
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	30.0	30.0
Carrying Value | Ark 2021 Notes
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	153.7	155.9
Carrying Value | Kudu Credit Facility
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	208.3	218.2
Carrying Value | Other Operations
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	$ 36.7	$ 16.8