Debt - Narrative (Details) € in Millions							1 Months Ended		3 Months Ended	4 Months Ended	6 Months Ended	12 Months Ended
	Jul. 21, 2025 USD ($)	Jul. 04, 2025 USD ($)	Apr. 29, 2022 USD ($)	Sep. 08, 2021 USD ($)	Aug. 11, 2021 USD ($)	Jul. 13, 2021 USD ($)	Jul. 31, 2023	Sep. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2025 USD ($) credit_facility	Dec. 31, 2025 USD ($) credit_facility	Dec. 31, 2026 USD ($)	Dec. 31, 2025 USD ($) credit_facility	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2025 EUR (€) credit_facility	Sep. 16, 2025 USD ($)	Sep. 02, 2025 USD ($)	Jul. 20, 2025	Jul. 16, 2025 USD ($)	Mar. 18, 2025	Sep. 17, 2024 USD ($)	Aug. 22, 2024 USD ($)	Jul. 31, 2024	Jun. 28, 2024 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Jun. 16, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jul. 13, 2021 EUR (€)	Mar. 23, 2021 USD ($)
Debt Instrument
Amount borrowed										$ 852,100,000	$ 852,100,000		$ 852,100,000
Debt										837,000,000.0	837,000,000.0		837,000,000.0	$ 562,500,000
Draw down of debt and revolving lines of credit													294,700,000	36,600,000	$ 12,400,000
Interest expense													78,400,000	60,800,000	62,700,000
Interest paid													66,400,000	61,000,000.0	42,200,000
Subsidiary - HG Global | Interest Rate Cap
Debt Instrument
Notational amount																							$ 150,000,000.0					$ 150,000,000.0
Interest rate																							10.76%					9.76%
Kudu (3) | Interest Rate Cap
Debt Instrument
Notational amount																						$ 150,000,000.0
Interest rate																						8.95%
Subsidiary - Distinguished | Interest Rate Cap
Debt Instrument
Notational amount																	$ 70,000,000.0
Interest rate																	10.50%
Ark 2021 Subordinated Notes
Debt Instrument
Debt										159,700,000	159,700,000		159,700,000	154,500,000
Ark 2021 Subordinated Notes | Subordinated Debt
Debt Instrument
Face value								$ 163,300,000	$ 163,300,000
Proceeds from debt, net of debt issuance costs									$ 157,800,000
Debt										159,700,000	159,700,000		159,700,000	154,500,000
Ark 2021 Subordinated Notes, Tranche 1 | Subordinated Debt
Debt Instrument
Face value						$ 46,300,000																								€ 39.1
Amount borrowed										45,800,000	45,800,000		45,800,000	41,100,000		€ 39.1
Ark 2021 Subordinated Notes, Tranche 1 | Subordinated Debt | Euro Interbank Offered Rate (EURIBOR)
Debt Instrument
Basis spread on variable rate						5.75%
Ark 2021 Subordinated Notes, Tranche 2 | Subordinated Debt
Debt Instrument
Face value					$ 47,000,000.0
Amount borrowed										47,000,000.0	47,000,000.0		47,000,000.0	47,000,000.0
Ark 2021 Subordinated Notes, Tranche 2 | Subordinated Debt | London Interbank Offered Rate (LIBOR)
Debt Instrument
Basis spread on variable rate					5.75%
Kudu Credit Facility
Debt Instrument
Debt										350,400,000	350,400,000		350,400,000	238,600,000
Kudu Credit Facility | Secured Debt
Debt Instrument
Face value	$ 500,000,000									300,000,000.0	300,000,000.0		300,000,000.0												$ 350,000,000.0						$ 300,000,000.0
Basis spread on variable rate	3.10%						0.26%
Amount borrowed										358,300,000	358,300,000		358,300,000	245,300,000	210,300,000											$ 215,200,000
Interest rate	7.25%						4.30%																	4.45%
Interest reserve account										$ 7,600,000	$ 7,600,000		$ 7,600,000	$ 15,100,000
Debt service coverage ratio										2.6	2.6		2.6	2.5		2.6					2.5
Debt covenant, loan to value percent	40.00%																		50.00%
Total interest rate							4.56%
Debt	$ 253,300,000									$ 350,400,000	$ 350,400,000		$ 350,400,000	$ 238,600,000
Floating rate	8.75%
Fixed rate	7.65%
Debt covenant, maximum loan to value percent										26.80%	26.80%		26.80%			26.80%
Percentage of borrowing base										35.00%	35.00%		35.00%			35.00%
Draw down of debt and revolving lines of credit													$ 113,000,000.0	35,000,000.0	$ 12,000,000.0
Kudu Credit Facility | Secured Debt | Maximum
Debt Instrument
Debt service coverage ratio										3.0	3.0		3.0			3.0
Kudu Credit Facility | Secured Debt | Debt Covenant, Period 1
Debt Instrument
Debt covenant, loan to value percent										40.00%	40.00%		40.00%			40.00%
Kudu Credit Facility | Secured Debt | Debt Covenant, Period 2
Debt Instrument
Debt covenant, loan to value percent										25.00%	25.00%		25.00%			25.00%
Kudu Credit Facility | Secured Debt | Debt Covenant, Period 3
Debt Instrument
Debt covenant, loan to value percent										15.00%	15.00%		15.00%			15.00%
Kudu Credit Facility | Secured Debt | Debt Covenant, Period 4
Debt Instrument
Debt covenant, loan to value percent										0.00%	0.00%		0.00%			0.00%
Kudu Credit Facility | Secured Debt | Secured Overnight Financing Rate (SOFR)
Debt Instrument
Basis spread on variable rate				0.26%	0.26%
Ark 2021 Subordinated Notes, Tranche 3 | Subordinated Debt
Debt Instrument
Face value				$ 70,000,000.0
Debt instrument, period for interest rate increase				10 years
Additional interest rate													1.00%
Solvency capital requirement								120.00%
Debt to capital requirement								40.00%
Amount borrowed										$ 70,000,000.0	$ 70,000,000.0		$ 70,000,000.0	70,000,000.0
Ark 2021 Subordinated Notes, Tranche 3 | Subordinated Debt | London Interbank Offered Rate (LIBOR)
Debt Instrument
Basis spread on variable rate				6.10%
Citibank LOC Facility | Line of Credit | Letter of Credit
Debt Instrument
Total commitment under revolving credit facility																													$ 125,000,000.0
Letters of credit outstanding										76,100,000	76,100,000		76,100,000
Pledged collateral										93,800,000	93,800,000		93,800,000
Lloyds LOC Facility | Line of Credit | Letter of Credit
Debt Instrument
Total commitment under revolving credit facility																											$ 100,000,000.0
Letters of credit outstanding										27,000,000.0	27,000,000.0		27,000,000.0
Pledged collateral										30,500,000	30,500,000		30,500,000
HG Global Senior Notes
Debt Instrument
Debt										147,800,000	147,800,000		$ 147,800,000	147,400,000
HG Global Senior Notes | Senior Notes
Debt Instrument
Face value			$ 150,000,000.0
Additional interest rate													1.00%
Amount borrowed										150,000,000.0	150,000,000.0		$ 150,000,000.0	150,000,000.0
Interest rate			6.00%
Anniversary of funding date			5 years
Annual payments			$ 15,000,000.0
Interest accrued multiplier																												8
Interest reserve account										30,400,000	30,400,000		30,400,000	29,300,000
Debt										147,800,000	147,800,000		147,800,000	147,400,000
HG Global Senior Notes | Senior Notes | Secured Overnight Financing Rate (SOFR)
Debt Instrument
Basis spread on variable rate			0.26%
Other Operations debt
Debt Instrument
Debt										38,300,000	38,300,000		38,300,000	22,000,000.0
Other Operations debt | Secured Debt
Debt Instrument
Amount borrowed										38,700,000	38,700,000		38,700,000	22,400,000
Debt										$ 38,300,000	$ 38,300,000		$ 38,300,000	22,000,000.0
Secured credit facilities | credit_facility										5	5		5			5
Distinguished Credit Facility
Debt Instrument
Debt										$ 129,900,000	$ 129,900,000		$ 129,900,000	0
Distinguished Credit Facility | Secured Debt
Debt Instrument
Face value		$ 141,000,000.0
Amount borrowed										$ 131,400,000	$ 131,400,000		$ 131,400,000	0				$ 90,200,000
Interest rate										5.50%	5.50%		5.50%			5.50%
Debt										$ 129,900,000	$ 129,900,000		$ 129,900,000	$ 0
Draw down of debt and revolving lines of credit		$ 50,000,000.0								$ 50,000,000.0
Debt instrument, periodic payment, principal											$ 400,000
Total leverage ratio		3.75								4.1	4.1		4.1			4.1
Distinguished Credit Facility | Secured Debt | Forecast
Debt Instrument
Debt instrument, periodic payment, principal												$ 1,400,000
Distinguished Credit Facility | Secured Debt | Minimum
Debt Instrument
Interest rate		5.25%
Distinguished Credit Facility | Secured Debt | Maximum
Debt Instrument
Interest rate		5.50%
Total leverage ratio										5.5	5.5		5.5			5.5
Distinguished Credit Facility | Secured Debt | Revolving Credit Facility
Debt Instrument
Total commitment under revolving credit facility		$ 15,000,000.0
Distinguished Credit Facility | Secured Debt | Delayed Draw Term Loan (DDTL)
Debt Instrument
Total commitment under revolving credit facility		$ 40,000,000.0
WTM Credit Facility | Revolving Credit Facility
Debt Instrument
Total commitment under revolving credit facility																				$ 250,000,000.0
WTM Credit Facility | Revolving Credit Facility | Minimum
Debt Instrument
Interest rate																				1.10%
WTM Credit Facility | Revolving Credit Facility | Maximum
Debt Instrument
Interest rate																				1.50%