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Investment Funds (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		18 Months Ended
	Jul. 01, 2022	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Unfunded commitments		$ 275,000		$ 275,000
Investment funds		1,589,119		1,589,119			$ 1,621,655
Income (Loss) from Investment Funds				(3,873)	$ 993
Written premiums ceded		590,993	$ 525,258	1,102,458	999,751
Fair Value
Schedule of Equity Method Investments [Line Items]
Trading account receivables from brokers and clearing organizations		40,705		40,705			303,614
Lifson Re
Schedule of Equity Method Investments [Line Items]
Percentage of reinsurance placements of share placed amounts	30.00%					22.50%
Written premiums ceded				206,000	281,000
Financial services
Schedule of Equity Method Investments [Line Items]
Investment funds		198,111		198,111			201,625
Income (Loss) from Investment Funds				12,880	2,963
Transportation
Schedule of Equity Method Investments [Line Items]
Investment funds		436,057		436,057			433,407
Income (Loss) from Investment Funds				(18,231)	(20,321)
Real Estate
Schedule of Equity Method Investments [Line Items]
Investment funds		306,485		306,485			344,278
Income (Loss) from Investment Funds				(3,732)	23,843
Energy
Schedule of Equity Method Investments [Line Items]
Investment funds		131,719		131,719			114,794
Income (Loss) from Investment Funds				8,505	3,439
Infrastructure
Schedule of Equity Method Investments [Line Items]
Investment funds		140,699		140,699			130,589
Income (Loss) from Investment Funds				7,828	5,936
Other funds
Schedule of Equity Method Investments [Line Items]
Investment funds		376,048		376,048			396,962
Income (Loss) from Investment Funds				(11,123)	$ (14,867)
Deferred compensation trust assets		$ 41,000		$ 41,000			$ 36,000

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Amount of written premiums ceded to other entities.

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