Fair Value of Financial Instruments Level 3 (Details) - Non-Agency MBS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period	$ 7,243	$ 10,927
Unrealized loss included in OCI	(1,850)	(1,733)
Principal payments	(5,071)	(4,351)
Balance at the end of the period	2,274	7,243
Interest Income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Accretion	$ 1,952	$ 2,400