Financial Derivatives (Schedule of Financial Derivatives) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	$ 18,894	$ 15,479
Financial derivatives–liabilities, at fair value-	(12,298)	(24,553)
Total	6,596	(9,074)
TBA Securities, Purchase Contracts [Member]
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	522	961
Financial derivatives–liabilities, at fair value-	(135)	0
TBA Securities, Sale Contracts [Member]
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	707	1
Financial derivatives–liabilities, at fair value-	(774)	(925)
Interest rate swaps | Short
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	11,871	125
Financial derivatives–liabilities, at fair value-	(6,567)	(15,109)
Interest rate swaps | Long
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	2,122	8,394
Financial derivatives–liabilities, at fair value-	(2,531)	(65)
Credit default swaps on asset-backed securities
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	303	347
Credit default swaps on asset-backed indices
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	1,751	2,184
Financial derivatives–liabilities, at fair value-	(39)	(130)
Credit default swaps on corporate bonds
Derivatives, Fair Value [Line Items]
Financial derivatives–liabilities, at fair value-	(99)	(747)
Credit default swaps on corporate bond indices
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	156	3,420
Financial derivatives–liabilities, at fair value-	(1,870)	(6,438)
Total return swaps
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	0	9
Financial derivatives–liabilities, at fair value-	0	(484)
Futures
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	478	2
Financial derivatives–liabilities, at fair value-	(75)	(376)
Futures | Short
Derivatives, Fair Value [Line Items]
Total	403	(374)
Forwards
Derivatives, Fair Value [Line Items]
Financial derivatives–liabilities, at fair value-	(208)	(279)
Warrants
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	706	36
Put Option [Member]
Derivatives, Fair Value [Line Items]
Financial derivatives–assets, at fair value-	$ 278	$ 0