Interest Receivable (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Interest receivable by investment category
Total interest receivable	$ 32,499	$ 35,828
Total MBS
Interest receivable by investment category
Total interest receivable	32,472	35,806
Fannie Mae
Interest receivable by investment category
Total interest receivable	12,599	13,760
Freddie Mac
Interest receivable by investment category
Total interest receivable	2,728	3,110
Ginnie Mae
Interest receivable by investment category
Total interest receivable	18	19
Non-Agency Mortgage Backed Securities
Interest receivable by investment category
Total interest receivable	17,127	18,917
Money market and other investments
Interest receivable by investment category
Total interest receivable	$ 27	$ 22