Fair Value of Financial Instruments Recorded basis and Fair Value (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage-backed securities		$ 2,921,444	$ 3,212,084
Derivative assets		368	28,534
Derivative liabilities		133	6,922
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage-backed securities			3,212,084
Mortgage loans held for investment, net (1)		16,523	19,036
Derivative assets		368	28,534
Repurchase agreements (2)		2,519,230	2,898,952
Non-recourse collateralized financing (1)		5,706	6,440
Derivative liabilities		133	6,922
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage-backed securities		2,921,444	3,212,084
Mortgage loans held for investment, net (1)	[1]	13,674	15,971
Derivative assets		368	28,534
Repurchase agreements (2)	[2]	2,519,230	2,898,952
Non-recourse collateralized financing (1)	[1]	5,722	6,357
Derivative liabilities		$ 133	$ 6,922

[1] The Company determines the fair value of its mortgage loans held for investment, net and its non-recourse collateralized financing using internally developed cash flow models with inputs similar to those used to estimate the fair value of the Company's Level 3 non-Agency MBS.

[2] The carrying value of repurchase agreements generally approximates fair value due to their short term maturities