Financial Derivatives (Credit Default Swaps) (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Derivative [Line Items]
Financial derivatives–assets, at fair value	$ 151,155	$ 184,395
Financial derivatives–liabilities, at fair value-	(60,763)	(71,024)
Fair Value	(90,392)	(113,371)
Credit default swaps on asset-backed indices
Derivative [Line Items]
Financial derivatives–assets, at fair value	2,033	1,825
Credit default swaps on asset-backed indices | Financial Derivatives - Assets | Long
Derivative [Line Items]
Notional Amount	(194)	(209)
Financial derivatives–assets, at fair value	$ 10	$ 11
Credit default swaps on asset-backed indices | Financial Derivatives - Assets | Long | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	12 years 2 months 26 days	12 years 11 months 26 days
Credit default swaps on asset-backed indices | Financial Derivatives - Assets | Short
Derivative [Line Items]
Notional Amount	$ (26,846)	$ (31,427)
Financial derivatives–assets, at fair value	$ 2,023	$ 1,814
Credit default swaps on asset-backed indices | Financial Derivatives - Assets | Short | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	33 years 3 months 14 days	34 years 7 months 6 days
Credit default swaps on corporate bonds
Derivative [Line Items]
Financial derivatives–assets, at fair value	$ 0	$ 83
Financial derivatives–liabilities, at fair value-	(177)	(225)
Credit default swaps on corporate bonds | Financial Derivatives - Assets | Long
Derivative [Line Items]
Notional Amount	0	(2,000)
Financial derivatives–assets, at fair value	0	$ 83
Credit default swaps on corporate bonds | Financial Derivatives - Assets | Long | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity		11 months 19 days
Credit default swaps on corporate bonds | Financial Derivatives - Liabilities | Short
Derivative [Line Items]
Notional Amount	(13,000)	$ (13,000)
Financial derivatives–liabilities, at fair value-	$ (177)	$ (225)
Credit default swaps on corporate bonds | Financial Derivatives - Liabilities | Short | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	1 year 8 months 19 days	2 years 5 months 19 days
Credit default swaps on corporate bond indices
Derivative [Line Items]
Financial derivatives–assets, at fair value	$ 13,412	$ 0
Financial derivatives–liabilities, at fair value-	(26,979)	(33,207)
Credit default swaps on corporate bond indices | Financial Derivatives - Assets | Long
Derivative [Line Items]
Notional Amount	(196,800)	0
Financial derivatives–assets, at fair value	$ 13,412	$ 0
Credit default swaps on corporate bond indices | Financial Derivatives - Assets | Long | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	4 years 1 month 24 days	0 days
Credit default swaps on corporate bond indices | Financial Derivatives - Liabilities | Short
Derivative [Line Items]
Notional Amount	$ (1,090,507)	$ (900,305)
Financial derivatives–liabilities, at fair value-	$ (26,979)	$ (33,207)
Remaining Years to Maturity	4 years 10 months 28 days	4 years 11 months 19 days
Credit default swaps
Derivative [Line Items]
Notional Amount	$ (933,405)	$ (942,569)
Fair Value	$ 11,714	$ 31,527
Credit default swaps | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	5 years 10 months 2 days	5 years 10 months 28 days