Basis of Presentation and Significant Accounting Policies Additional Information (Details) - USD ($)		12 Months Ended
	Apr. 29, 1991	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2019	Oct. 31, 2025	Dec. 31, 2022	Apr. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Operating Lease, Liability		$ 9,854,000	$ 21,543,000
Common Stock Voting Restrictions	10.00%
Common stock, par value (in dollars per share)								$ 0.01
Preferred stock, shares authorized		20,000,000	20,000,000
Preferred Stock, Par or Stated Value Per Share		$ 0.01						$ 0.01
Common stock, shares issued		48,876,882	48,875,167
Common Stock Transfer Restrictions	5.00%
Common Stock Additional Transfer Restrictions					5.00%
Restricted Cash		$ 40,754,000	$ 17,669,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		70,090,000	47,275,000	$ 19,223,000			$ 19,940,000
Investment income due and accrued		$ 1,432,000	$ 1,703,000
Accrued Investment Interest Receivable Write-off Period in Days		90
Financial Assets Allowance for Credit Loss		$ 950,000
Preferred stock, shares outstanding (in shares)		0	0
Short-Term Debt		$ 0	$ 150,000,000
Debt Instrument, Convertible, Type of Equity Security		3,500
Investment in less than 100 percent owned, Percentage		$ 0.74
Investments, Equity Interest Percent		17.00%
Long-term debt		$ 117,558,000	0			$ 100,000,000
Adjustment of NCI to fair value			(10,276,000)
Put / call option exercise		$ (1,815,000)
Number of Put Options Exercised During Period		0
Investment income due and accrued		$ 1,432,000	1,703,000
CECL Securities Factor for Consideration		20.00%
Medium-Term Note
Finite-Lived Intangible Assets [Line Items]
Long-term debt		$ 100,000,000
Revolving Credit Facility
Finite-Lived Intangible Assets [Line Items]
Short-Term Debt		$ 20,000,000				$ 20,000,000
Specialty Property & Casualty Program
Finite-Lived Intangible Assets [Line Items]
Reinsurance, Reinsured Risk, Percentage		70.00%
Xchange
Finite-Lived Intangible Assets [Line Items]
Ownership percentage		80.00%
All Trans
Finite-Lived Intangible Assets [Line Items]
Ownership percentage		85.00%
Capacity Marine
Finite-Lived Intangible Assets [Line Items]
Ownership percentage		80.00%
Riverton
Finite-Lived Intangible Assets [Line Items]
Ownership percentage		80.00%
Pivix
Finite-Lived Intangible Assets [Line Items]
Ownership percentage		74.00%
Octave Ventures
Finite-Lived Intangible Assets [Line Items]
Ownership percentage		60.00%
Minimum [Member] | Furniture and Fixtures [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life in Years		3 years
Maximum [Member] | Furniture and Fixtures [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life in Years		5 years
Long-term Debt [Member]
Finite-Lived Intangible Assets [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities		$ 19,775,000	$ 3,821,000	$ 0