Financial Derivatives (Credit Default Swaps) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Derivative [Line Items]
Financial derivatives–assets, at fair value-	$ 65,082	$ 18,894
Financial derivatives–liabilities, at fair value-	(16,528)	(12,298)
Fair Value	(48,554)	(6,596)
Credit default swaps on asset-backed indices
Derivative [Line Items]
Financial derivatives–assets, at fair value-	1,193	1,751
Financial derivatives–liabilities, at fair value-	(38)	(39)
Credit default swaps on asset-backed indices | Financial Derivatives - Liabilities | Short
Derivative [Line Items]
Notional Amount	(1)	(491)
Financial derivatives–liabilities, at fair value-	$ 0	$ 0
Credit default swaps on asset-backed indices | Financial Derivatives - Liabilities | Short | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	27 years 9 months 3 days	24 years 5 months 1 day
Credit default swaps on asset-backed indices | Financial Derivatives - Assets | Short
Derivative [Line Items]
Notional Amount	$ (10,471)	$ (13,947)
Financial derivatives–assets, at fair value-	$ 1,187	$ 1,744
Credit default swaps on asset-backed indices | Financial Derivatives - Assets | Short | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	43 years 4 months 6 days	42 years 5 months 4 days
Credit default swaps on asset-backed securities
Derivative [Line Items]
Financial derivatives–assets, at fair value-	$ 304	$ 303
Credit default swaps on asset-backed securities | Financial Derivatives - Assets | Short
Derivative [Line Items]
Notional Amount	(912)	(910)
Financial derivatives–assets, at fair value-	$ 304	$ 303
Credit default swaps on asset-backed securities | Financial Derivatives - Assets | Short | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	13 years 5 months 15 days	13 years 8 months 15 days
Credit default swaps
Derivative [Line Items]
Notional Amount	$ (67,259)	$ (37,190)
Fair Value	$ 1,792	$ (202)
Credit default swaps | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	10 years 8 months 19 days	19 years 1 month 6 days
Credit default swaps on corporate bond indices
Derivative [Line Items]
Financial derivatives–assets, at fair value-	$ 154	$ 156
Financial derivatives–liabilities, at fair value-	(3,321)	(1,870)
Credit default swaps on corporate bond indices | Financial Derivatives - Liabilities | Short
Derivative [Line Items]
Notional Amount	(53,589)	(21,183)
Financial derivatives–liabilities, at fair value-	$ (3,321)	$ (1,870)
Credit default swaps on corporate bond indices | Financial Derivatives - Liabilities | Short | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity	4 years 9 months 25 days	4 years 9 months
Credit default swaps on corporate bond indices | Financial Derivatives - Assets | Short
Derivative [Line Items]
Notional Amount	$ (1,550)	$ 0
Financial derivatives–assets, at fair value-	$ 51	$ 0
Remaining Years to Maturity	1 year 8 months 19 days
Credit default swaps on corporate bond indices | Financial Derivatives - Assets | Short | Weighted Average
Derivative [Line Items]
Remaining Years to Maturity		0 days