Derivative Financial Instruments - Summary of TBA Contracts - 30 Year [Member]	Mar. 31, 2016 USD ($)
Derivatives, Fair Value [Line Items]
Notional Amount	$ (235,000,000)
Cost Basis	(255,141,000)
Market Value Of TBA Contract	(255,324,000)
Assets, at Fair Value	(183,000)
4.0% [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	(232,000,000)
Cost Basis	(251,938,000)
Market Value Of TBA Contract	(252,116,000)
Assets, at Fair Value	(178,000)
4.5% [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	(3,000,000)
Cost Basis	(3,203,000)
Market Value Of TBA Contract	(3,208,000)
Assets, at Fair Value	$ (5,000)