Interest Receivable (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Interest receivable by investment category
Interest receivable	$ 34,673	$ 35,828
Total MBS
Interest receivable by investment category
Interest receivable	34,598	35,806
Fannie Mae.
Interest receivable by investment category
Interest receivable	13,638	13,760
Freddie Mac.
Interest receivable by investment category
Interest receivable	2,872	3,110
Ginnie Mae.
Interest receivable by investment category
Interest receivable	19	19
Non-Agency MBS
Interest receivable by investment category
Interest receivable	18,069	18,917
Money market and other investments
Interest receivable by investment category
Interest receivable	$ 75	$ 22