Financial Derivatives (TBAs) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Financial derivatives–assets, at fair value-	$ 11,150	$ 20,001
Derivative Liability	27,805	$ 20,806
Derivative Assets (Liabilities), at Fair Value, Net	(16,655)
TBA securities
Derivative [Line Items]
Notional Amount	553,237
Derivative, Cost Basis	(571,376)
Market Value Underlying	(573,679)
Derivative Assets (Liabilities), at Fair Value, Net	(2,303)
TBA securities | Long
Derivative [Line Items]
Notional Amount	107,101
Derivative, Cost Basis	110,827
Market Value Underlying	110,948
Derivative Assets (Liabilities), at Fair Value, Net	121
TBA securities | Short
Derivative [Line Items]
Notional Amount	660,338
Derivative, Cost Basis	(682,203)
Market Value Underlying	(684,627)
Derivative Assets (Liabilities), at Fair Value, Net	(2,424)
Financial Derivatives - Assets | TBA securities | Long
Derivative [Line Items]
Notional amount, assets	107,101
Derivative, Cost Basis	110,827
Market Value Underlying	110,948
Financial derivatives–assets, at fair value-	121
Financial Derivatives - Assets | TBA securities | Short
Derivative [Line Items]
Notional amount, assets	7,100
Derivative, Cost Basis	(7,278)
Market Value Underlying	(7,259)
Financial derivatives–assets, at fair value-	19
Financial Derivatives - Liabilities | TBA securities | Short
Derivative [Line Items]
Notional amount, liabilities	(653,238)
Derivative, Cost Basis	(674,925)
Market Value Underlying	(677,368)
Derivative Liability	$ (2,443)