Financial Derivatives (Schedule of Financial Derivatives) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	$ 104,033	$ 132,518
Financial derivatives–liabilities, at fair value-	(24,245)	(54,198)
Total	79,788	78,320
TBA Securities, Purchase Contracts [Member]
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	1,482	0
Financial derivatives–liabilities, at fair value-	(15)	(2,007)
TBA Securities, Sale Contracts [Member]
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	42	7,985
Financial derivatives–liabilities, at fair value-	(5,608)	0
Interest rate swaps | Short
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	80,708	116,768
Financial derivatives–liabilities, at fair value-	(2,360)	(1,408)
Interest rate swaps | Long
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	15,691	254
Financial derivatives–liabilities, at fair value-	(10,851)	(48,882)
Credit default swaps on asset-backed securities
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	76	76
Credit default swaps on asset-backed indices
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	4,846	3,366
Financial derivatives–liabilities, at fair value-	(33)	(33)
Credit default swaps on corporate bonds
Derivatives, Fair Value [Line Items]
Financial derivatives–liabilities, at fair value-	(277)	(259)
Credit default swaps on corporate bond indices
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	44	83
Financial derivatives–liabilities, at fair value-	(1,720)	(1,513)
Futures
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	88	2,772
Financial derivatives–liabilities, at fair value-	(3,076)	(96)
Futures | Short
Derivatives, Fair Value [Line Items]
Total	(2,988)	2,676
Forwards
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	0	77
Financial derivatives–liabilities, at fair value-	(305)	0
Warrants
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	$ 1,056	$ 1,137