Fair Value of Financial Instruments Level 3 (Details) - Fair Value, Measurements, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period	$ 43,957
Unrealized (loss) gain included in OCI	1,762
Principal payments	(23,375)
Accretion	289
Balance at the end of the period	22,633
Non-Agency CMBS [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period	42,033
Unrealized (loss) gain included in OCI	1,770
Principal payments	(23,201)
Accretion	289
Balance at the end of the period	20,891
Non-Agency RMBS [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period	1,924
Unrealized (loss) gain included in OCI	(8)
Principal payments	(174)
Accretion	0
Balance at the end of the period	$ 1,742