Residential Mortgage-Backed Securities (Details 3) (USD $) In Thousands, unless otherwise specified	1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2013
Components of interest income
Net (Premium Amortization/Amortization Basis) Discount Amortization	$ (1,567)		$ (14,199)
Interest Income	7,083	32,742	66,492
Residential Mortgage-Backed Securities
Components of interest income
Coupon Interest	8,912	46,411	97,412
Net (Premium Amortization/Amortization Basis) Discount Amortization	(1,829)	(13,669)	(30,920)
Interest Income	7,083	32,742	66,492
Agency RMBS
Components of interest income
Coupon Interest	8,912	45,788	96,307
Net (Premium Amortization/Amortization Basis) Discount Amortization	(1,829)	(15,380)	(33,729)
Interest Income	7,083	30,408	62,578
Non-Agency RMBS
Components of interest income
Coupon Interest		623	1,105
Net (Premium Amortization/Amortization Basis) Discount Amortization		1,711	2,809
Interest Income		$ 2,334	$ 3,914