Financial Derivatives (TBAs) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Financial derivatives–assets, at fair value-	$ 16,788	$ 20,001
Derivative Liability	27,621	$ 20,806
Derivative Assets (Liabilities), at Fair Value, Net	(10,833)
TBA securities
Derivative [Line Items]
Notional Amount	1,053,630
Derivative, Cost Basis	(1,098,063)
Market Value Underlying	(1,098,479)
Derivative Assets (Liabilities), at Fair Value, Net	(416)
TBA securities | Long
Derivative [Line Items]
Notional Amount	40,100
Derivative, Cost Basis	40,585
Market Value Underlying	40,675
Derivative Assets (Liabilities), at Fair Value, Net	90
TBA securities | Short
Derivative [Line Items]
Notional Amount	1,093,730
Derivative, Cost Basis	(1,138,648)
Market Value Underlying	(1,139,154)
Derivative Assets (Liabilities), at Fair Value, Net	(506)
Financial Derivatives - Assets | TBA securities | Long
Derivative [Line Items]
Notional Amount	40,100
Derivative, Cost Basis	40,585
Market Value Underlying	40,675
Financial derivatives–assets, at fair value-	90
Financial Derivatives - Assets | TBA securities | Short
Derivative [Line Items]
Notional Amount	319,981
Derivative, Cost Basis	(332,080)
Market Value Underlying	(331,574)
Financial derivatives–assets, at fair value-	506
Financial Derivatives - Liabilities | TBA securities | Short
Derivative [Line Items]
Notional Amount	773,749
Derivative, Cost Basis	(806,568)
Market Value Underlying	(807,580)
Derivative Liability	$ (1,012)