Financial Derivatives (Schedule of Credit Derivatives) (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Credit Derivatives [Line Items]
Financial derivatives–assets, at fair value	$ 151,155	$ 184,395
Derivative Liability	(60,763)	(71,024)
Derivative Assets (Liabilities), at Fair Value, Net	90,392	113,371
Credit default swaps on asset-backed indices
Credit Derivatives [Line Items]
Financial derivatives–assets, at fair value	2,033	1,825
Credit default swaps on asset-backed indices | Financial Derivatives - Assets | Long
Credit Derivatives [Line Items]
Notional value	194	209
Financial derivatives–assets, at fair value	$ 10	$ 11
Credit default swaps on asset-backed indices | Financial Derivatives - Assets | Long | Weighted Average
Credit Derivatives [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
Credit Derivatives [Line Items]
Notional value	$ 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
Credit Derivatives [Line Items]
Remaining Years to Maturity	33 years 3 months 14 days	34 years 7 months 6 days
Credit default swaps on corporate bond indices
Credit Derivatives [Line Items]
Financial derivatives–assets, at fair value	$ 13,412	$ 0
Derivative Liability	(26,979)	(33,207)
Credit default swaps on corporate bond indices | Financial Derivatives - Assets | Long
Credit Derivatives [Line Items]
Notional value	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
Credit Derivatives [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
Credit Derivatives [Line Items]
Notional value	$ 1,090,507	$ 900,305
Remaining Years to Maturity	4 years 10 months 28 days	4 years 11 months 19 days
Derivative Liability	$ (26,979)	$ (33,207)
Credit default swaps on corporate bonds
Credit Derivatives [Line Items]
Financial derivatives–assets, at fair value	0	83
Derivative Liability	(177)	(225)
Credit default swaps on corporate bonds | Financial Derivatives - Assets | Long
Credit Derivatives [Line Items]
Notional value	0	2,000
Financial derivatives–assets, at fair value	0	$ 83
Credit default swaps on corporate bonds | Financial Derivatives - Assets | Long | Weighted Average
Credit Derivatives [Line Items]
Remaining Years to Maturity		11 months 19 days
Credit default swaps on corporate bonds | Financial Derivatives - Liabilities | Short
Credit Derivatives [Line Items]
Notional value	13,000	$ 13,000
Derivative Liability	$ (177)	$ (225)
Credit default swaps on corporate bonds | Financial Derivatives - Liabilities | Short | Weighted Average
Credit Derivatives [Line Items]
Remaining Years to Maturity	1 year 8 months 19 days	2 years 5 months 19 days
Credit default swaps
Credit Derivatives [Line Items]
Notional value	$ 933,405	$ 942,569
Derivative Assets (Liabilities), at Fair Value, Net	$ (11,714)	$ (31,527)
Credit default swaps | Weighted Average
Credit Derivatives [Line Items]
Remaining Years to Maturity	5 years 10 months 2 days	5 years 10 months 28 days
Credit Default Swap, Asset Backed Securities
Credit Derivatives [Line Items]
Derivative Liability	$ (3)	$ (3)
Credit Default Swap, Asset Backed Securities | Financial Derivatives - Liabilities | Short
Credit Derivatives [Line Items]
Notional value	46	46
Derivative Liability	$ (3)	$ (3)
Credit Default Swap, Asset Backed Securities | Financial Derivatives - Liabilities | Short | Weighted Average
Credit Derivatives [Line Items]
Remaining Years to Maturity	9 years 11 months 26 days	10 years 8 months 26 days
Credit Default Swap, Selling Protection [Member]
Credit Derivatives [Line Items]
Fair Value	$ 13,422	$ 94
Notional value	$ 196,994	$ 2,209