Fair Value of Financial Instruments Level 3 (Details) (Fair Value, Measurements, Recurring [Member], Fair Value, Inputs, Level 3 [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
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	89
Principal payments	(2,347)
Accretion	90
Balance at the end of the period	41,789
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	96
Principal payments	(2,299)
Accretion	90
Balance at the end of the period	39,920
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	(7)
Principal payments	(48)
Accretion	0
Balance at the end of the period	$ 1,869