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Debt - Narrative (Details) € in Millions					1 Months Ended			3 Months Ended				6 Months Ended
Debt - Narrative (Details) € in Millions	Jan. 24, 2025 USD ($)	Apr. 29, 2022 USD ($)	Sep. 08, 2021 USD ($)	Aug. 11, 2021 USD ($)	Jul. 31, 2023	Sep. 30, 2021 USD ($)	Jul. 31, 2021	Jun. 30, 2025 USD ($) credit_facility	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Sep. 30, 2021 USD ($) transaction	Jun. 30, 2025 USD ($) credit_facility	Jun. 30, 2024 USD ($)	Dec. 31, 2025	Jun. 30, 2025 EUR (€) credit_facility	Mar. 18, 2025	Mar. 12, 2025 USD ($)	Dec. 31, 2024 USD ($)	Sep. 17, 2024 USD ($)	Aug. 22, 2024 USD ($)	Jul. 31, 2024	Jun. 28, 2024 USD ($)	Sep. 30, 2022 USD ($)	Jun. 16, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jul. 13, 2021 USD ($)	Jul. 13, 2021 EUR (€)	Mar. 23, 2021 USD ($)	Mar. 31, 2007 USD ($)
Debt Instrument
Repayments of notes												$ 2,300,000	$ 34,100,000
Subsidiary - HG Global \| Interest Rate Cap
Debt Instrument
Notional amount																				$ 150,000,000				$ 150,000,000
Maximum interest rate																				10.76%				9.76%
Kudu \| Interest Rate Cap
Debt Instrument
Notional amount																			$ 150,000,000
Maximum interest rate																			8.95%
Subsidiary - Bamboo \| Interest Rate Cap
Debt Instrument
Notional amount																	$ 80,000,000
Maximum interest rate																	10.00%
Ark 2007 Subordinated Notes \| Junior Subordinated Debt
Debt Instrument
Face value																													$ 30,000,000
Repayments of notes										$ 30,000,000
Ark 2021 Subordinated Notes \| Subordinated Debt
Debt Instrument
Face value						$ 163,300,000					$ 163,300,000
Number of transactions \| transaction											3
Proceeds from debt, net of debt issuance costs											$ 157,800,000
Ark 2021 Subordinated Notes Tranche 1 \| Subordinated Debt
Debt Instrument
Face value																										$ 46,300,000	€ 39.1
Amount borrowed								$ 45,300,000				45,300,000			€ 39.1			$ 41,100,000
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
Amount borrowed								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 \| Secured Debt
Debt Instrument
Face value																						$ 350,000,000						$ 300,000,000.0
Repayments of notes								0	$ 0			0	$ 0
Basis spread on variable rate					0.26%
Amount borrowed								253,300,000				253,300,000						245,300,000
Stated margin					4.30%																4.45%
Interest reserve account								$ 7,800,000				$ 7,800,000						$ 15,100,000
Debt service coverage ratio								2.8				2.8			2.8	2.5		2.5
Total interest rate					4.56%
Debt covenant, maximum loan to value percent								22.20%				22.20%			22.20%
Percentage of borrowing base								35.00%				35.00%			35.00%
Kudu Credit Facility \| Secured Debt \| Forecast
Debt Instrument
Debt service coverage ratio														3.0
Kudu Credit Facility \| Secured Debt \| Debt Covenant, Period 1
Debt Instrument
Debt covenant, loan to value percent								50.00%				50.00%			50.00%
Kudu Credit Facility \| Secured Debt \| Debt Covenant, Period 2
Debt Instrument
Debt covenant, loan to value percent								40.00%				40.00%			40.00%
Kudu Credit Facility \| Secured Debt \| Debt Covenant, Period 3
Debt Instrument
Debt covenant, loan to value percent								25.00%				25.00%			25.00%
Kudu Credit Facility \| Secured Debt \| Debt Covenant, Period 4
Debt Instrument
Debt covenant, loan to value percent								15.00%				15.00%			15.00%
Kudu Credit Facility \| Secured Debt \| Debt Covenant, Period 5
Debt Instrument
Debt covenant, loan to value percent								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
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
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
Letters of credit outstanding								82,700,000				82,700,000
Pledged collateral								104,400,000				104,400,000
Lloyds LOC Facility \| Line of Credit \| Letter of Credit
Debt Instrument
Total commitment under revolving credit facility																							$ 100,000,000
Letters of credit outstanding								27,600,000				27,600,000
Pledged collateral								38,700,000				$ 38,700,000
HG Global Senior Notes \| Senior Notes
Debt Instrument
Face value		$ 150,000,000
Additional interest rate												1.00%
Amount borrowed								150,000,000.0				$ 150,000,000.0						150,000,000.0
Stated margin		6.00%
Anniversary of funding date		5 years
Annual payments		$ 15,000,000
Interest accrued multiplier																								8
Interest reserve account, maximum								29,300,000				29,300,000
Interest reserve account								29,300,000				29,300,000						29,300,000
HG Global Senior Notes \| Senior Notes \| Secured Overnight Financing Rate (SOFR)
Debt Instrument
Basis spread on variable rate		0.26%
Bamboo Credit Facility \| Secured Debt
Debt Instrument
Face value	$ 110,000,000
Repayments of notes								300,000				300,000
Amount borrowed								$ 109,700,000				$ 109,700,000						0
Stated margin								4.50%				4.50%			4.50%
Annual payments	$ 1,100,000
Debt instrument, term	6 years
Debt instrument, periodic payment, principal	$ 800,000
Total leverage ratio	1.5							0.9				0.9			0.9
Bamboo Credit Facility \| Secured Debt \| Minimum
Debt Instrument
Stated margin	4.50%
Bamboo Credit Facility \| Secured Debt \| Maximum
Debt Instrument
Stated margin	5.00%
Total leverage ratio								4.5				4.5			4.5
Bamboo Credit Facility \| Secured Debt \| Revolving Credit Facility
Debt Instrument
Total commitment under revolving credit facility	$ 10,000,000
Other Operations debt \| Secured Debt
Debt Instrument
Amount borrowed								$ 37,300,000				$ 37,300,000						$ 22,400,000
Secured credit facilities \| credit_facility								5				5			5