Derivative Instruments Schedule of TBA Securities (Details) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Derivative [Line Items] | |||||||||||||
| Financial derivatives–assets, at fair value | [1] | $ 2,183 | $ 3,072 | ||||||||||
| Financial derivatives–liabilities, at fair value | [1] | (4,725) | (8,700) | ||||||||||
| Derivative, Fair Value, Net | (2,542) | (5,628) | |||||||||||
| TBA securities- purchase contracts [Member] | |||||||||||||
| Derivative [Line Items] | |||||||||||||
| Derivative notional | [2] | 83,709 | 68,319 | ||||||||||
| Derivative cost basis | [3] | 85,846 | 70,360 | ||||||||||
| Market Value, Underyling | [4] | 85,912 | 70,742 | ||||||||||
| Derivative, Fair Value, Net | [5] | 66 | 382 | ||||||||||
| TBA securities- sale contracts [Member] | |||||||||||||
| Derivative [Line Items] | |||||||||||||
| Derivative notional | [2] | (423,546) | (605,076) | ||||||||||
| Derivative cost basis | [3] | (450,449) | (644,949) | ||||||||||
| Market Value, Underyling | [4] | (450,462) | (646,529) | ||||||||||
| Derivative, Fair Value, Net | [5] | (13) | (1,580) | ||||||||||
| TBA securities [Member] | |||||||||||||
| Derivative [Line Items] | |||||||||||||
| Derivative notional, net | [2] | (339,837) | (536,757) | ||||||||||
| Derivative cost basis | [3] | (364,603) | (574,589) | ||||||||||
| Market Value, Underyling | [4] | (364,550) | (575,787) | ||||||||||
| Derivative, Fair Value, Net | [5] | 53 | (1,198) | ||||||||||
| Derivative Financial Instruments, Assets [Member] | TBA securities- purchase contracts [Member] | |||||||||||||
| Derivative [Line Items] | |||||||||||||
| Derivative notional | [2] | 60,291 | 53,319 | ||||||||||
| Derivative cost basis | [3] | 61,638 | 54,757 | ||||||||||
| Market Value, Underyling | [4] | 61,753 | 55,144 | ||||||||||
| Financial derivatives–assets, at fair value | [5] | 115 | 387 | ||||||||||
| Derivative Financial Instruments, Assets [Member] | TBA securities- sale contracts [Member] | |||||||||||||
| Derivative [Line Items] | |||||||||||||
| Derivative notional | [2] | (170,800) | (79,090) | ||||||||||
| Derivative cost basis | [3] | (181,476) | (85,730) | ||||||||||
| Market Value, Underyling | [4] | (181,174) | (85,641) | ||||||||||
| Financial derivatives–assets, at fair value | [5] | 302 | 89 | ||||||||||
| Derivative Financial Instruments, Liabilities [Member] | TBA securities- purchase contracts [Member] | |||||||||||||
| Derivative [Line Items] | |||||||||||||
| Derivative notional | [2] | 23,418 | 15,000 | ||||||||||
| Derivative cost basis | [3] | 24,208 | 15,603 | ||||||||||
| Market Value, Underyling | [4] | 24,159 | 15,598 | ||||||||||
| Financial derivatives–liabilities, at fair value | [5] | (49) | (5) | ||||||||||
| Derivative Financial Instruments, Liabilities [Member] | TBA securities- sale contracts [Member] | |||||||||||||
| Derivative [Line Items] | |||||||||||||
| Derivative notional | [2] | (252,746) | (525,986) | ||||||||||
| Derivative cost basis | [3] | (268,973) | (559,219) | ||||||||||
| Market Value, Underyling | [4] | (269,288) | (560,888) | ||||||||||
| Financial derivatives–liabilities, at fair value | [5] | $ (315) | $ (1,669) | ||||||||||
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