Financial Derivatives (Schedule of Financial Derivatives) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	$ 150,343	$ 143,996
Financial derivatives–liabilities, at fair value-	(40,425)	(61,776)
Total	109,918	82,220
TBA Securities, Purchase Contracts [Member]
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	13	2,182
Financial derivatives–liabilities, at fair value-	(189)	0
TBA Securities, Sale Contracts [Member]
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	866	0
Financial derivatives–liabilities, at fair value-	(380)	(5,820)
Interest rate swaps | Short
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	126,002	101,881
Financial derivatives–liabilities, at fair value-	(3,360)	(17,944)
Interest rate swaps | Long
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	9,113	27,358
Financial derivatives–liabilities, at fair value-	(13,293)	(13,801)
Credit default swaps on asset-backed securities
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	8	8
Credit default swaps on asset-backed indices
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	1,948	3,318
Financial derivatives–liabilities, at fair value-	(32)	(32)
Credit default swaps on corporate bonds
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	107	25
Financial derivatives–liabilities, at fair value-	(246)	(225)
Credit default swaps on corporate bond indices
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	11,830	7,259
Financial derivatives–liabilities, at fair value-	(22,037)	(15,894)
Total return swaps
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	6	6
Futures
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	61	245
Financial derivatives–liabilities, at fair value-	(888)	(7,990)
Futures | Short
Derivatives, Fair Value [Line Items]
Total	(827)	(7,745)
Forwards
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	336	12
Financial derivatives–liabilities, at fair value-	0	70
Warrants
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value	$ 53	$ 1,702