Collateral Positions (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Collateral Positions
Assets Pledged	$ 11,583,809	$ 10,058,769
Collateral Held	498,336	512,105
Derivative Hedging Instruments
Collateral Positions
Assets Pledged	111,954	123,733
Derivative Hedging Instruments \| Agency Mortgage Backed Securities
Collateral Positions
Assets Pledged	44,621	57,247
Derivative Hedging Instruments \| Cash
Collateral Positions
Assets Pledged	67,333	66,486
Repurchase Agreement Borrowings
Collateral Positions
Assets Pledged	11,471,855	9,935,036
Repurchase Agreement Borrowings \| Agency Mortgage Backed Securities
Collateral Positions
Assets Pledged	4,923,712	5,462,566
Repurchase Agreement Borrowings \| Legacy Non-Agency MBS
Collateral Positions
Assets Pledged	3,139,828	3,491,312
Non-Agency MBS acquired from consolidated VIEs	587,100	1,275,000
Non-Agency MBS pledged as collateral in connection with contemporaneous repurchase and reverse repurchase agreements entered into with a single counterparty	723,600	731,000
Repurchase Agreement Borrowings \| RPL/NPL MBS
Collateral Positions
Assets Pledged	2,591,503	160,688
Repurchase Agreement Borrowings \| U.S. Treasury securities
Collateral Positions
Assets Pledged	498,336	512,105
Repurchase Agreement Borrowings \| CRT securities
Collateral Positions
Assets Pledged	116,690	94,610
Repurchase Agreement Borrowings \| Residential whole loans
Collateral Positions
Assets Pledged	201,062	212,986
Repurchase Agreement Borrowings \| Cash
Collateral Positions
Assets Pledged	724	769
Reverse Repurchase Agreements
Collateral Positions
Collateral Held	498,336	512,105
Reverse Repurchase Agreements \| U.S. Treasury securities
Collateral Positions
Collateral Held	$ 498,336	$ 512,105

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- Definition

For an unclassified balance sheet, represents investments in debt and equity securities, categorized neither as held-to-maturity nor trading, which are acquired from a consolidated variable interest entity and eliminated on the entity's consolidated balance sheet.

+ References

No definition available.

+ Details

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- Definition

Represents the non-agency MBS pledged as collateral in connection with contemporaneous repurchase and reverse repurchase agreements entered into with a single counterparty.

+ References

No definition available.

+ Details

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- Definition

The carrying amount, as of the date of the latest financial statement presented, of all assets that are pledged as collateral for the payment of the related debt obligation primarily arising from secured borrowings, repurchase agreements or other current or potential obligations, where the secured party does not have the right by contract or custom to sell or re-pledge the collateral and therefore are not reclassified and separately reported in the statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 50

-Paragraph 1A

-Subparagraph (b)(1)(i)

-URI http://asc.fasb.org/extlink&oid=55761124&loc=SL6224234-111729

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- Definition

The carrying amount (fair value) as of the balance sheet date of securities held that had been pledged by counterparties under financing and lending arrangements, pursuant to which the entity has the right by agreement or custom to sell or re-pledge such securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5086-111524

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