CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Residential whole loans, pledged as collateral	$ 67,536us-gaap_LoansPledgedAsCollateral	$ 0us-gaap_LoansPledgedAsCollateral
Residential whole loans, pledged as collateral, fair value	143,072	0
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	8,050,000us-gaap_PreferredStockSharesAuthorized	8,050,000us-gaap_PreferredStockSharesAuthorized
Preferred stock, dividend rate (as a percent)	7.50%	7.50%
Preferred stock, shares issued	8,000,000us-gaap_PreferredStockSharesIssued	8,000,000us-gaap_PreferredStockSharesIssued
Preferred stock, shares outstanding	8,000,000us-gaap_PreferredStockSharesOutstanding	8,000,000us-gaap_PreferredStockSharesOutstanding
Preferred stock, aggregate liquidation preference (in dollars)	200,000	200,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	886,950,000us-gaap_CommonStockSharesAuthorized	886,950,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	370,084,000us-gaap_CommonStockSharesIssued	365,125,000us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	370,084,000us-gaap_CommonStockSharesOutstanding	365,125,000us-gaap_CommonStockSharesOutstanding
Agency MBS
Mortgage backed securities pledged as collateral	5,519,813	6,142,306
Non-Agency MBS
Mortgage backed securities pledged as collateral	2,377,343	1,778,067
CRT securities
Mortgage backed securities pledged as collateral	$ 94,610	$ 0

The fair value of available-for-sale securities that serve as collateral for borrowings.

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Face amount or stated value per share of common stock.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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The fair value, as of the date of each statement of financial position presented, of loans which are owned but transferred to serve as collateral for the payment of the related debt obligation primarily arising from secured borrowings and repurchase agreements, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

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The percentage rate used to calculate dividend payments on preferred stock.

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Value of the difference between preference in liquidation and the par or stated values of the preferred shares.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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